No fandom wants to see a ship they've loved, supported and fought for replaced.
For us, the departure of Elena could well mean kissing the hopes of a happy ending for our ship goodbye forever. But it could also mean something else: the potential for a new romance - whether that be a hook-up or more - for Bamon.
The animosity between DE fans and Bamon fans has been a long-standing one. In some cases, I would argue that the biggest ship war has been with Bamon, not Stelena. DE and Bamon fans simply do not get along due to their totally conflicting perspectives and understanding of the characters. Bamon fans like to think they are the most caring and sharing of fandoms in the TVD world, and whenever you mention any of the things they might have said about Damon, or Elena, or DE shippers, they are very quick to point the finger back at us and claim that it's the DE shippers who are the worst; and we're the ones to blame. I doubt the 'Bamonators' (as they like to call themselves), care that Nina is leaving at the end of the season. They continually refer to Elena as 'Doppel' (or at least they used to when Katherine was still around), and they call DE 'Dullena'. (Is it any wonder we don't like them?!) Ever since the show began, there was this great expectation from the Bamon shippers that they were in for great things. It would be just like the books! Damon was going to save Bonnie from danger, put Bonnie in the bath and call her 'red bird'! Damon was going to fall in love with Bonnie and ditch Elena and Bamon were going to skip hand-in-hand into the sunset together. But it wasn't like that.
Any time Damon was as much in a scene with Bonnie - (and they didn't even have to be interacting) - Bamon fans would get hysterical with joy. I can't speak for the whole DE fandom, but I know I was baffled by their reaction. Nevertheless, this might have been OK, had the Bamon fans not already decided that Damon was better off with Bonnie - even though at the time, they weren't even friends. Now, a lot of you may not have joined fanpop at the time, but I remember back when a certain someone on the Bamon spot would post articles attacking Delena mercilessly every week, condemning them, and arguing that they were unhealthy and destructive, and Elena molly-coddled Damon and let him get away with everything, and that Damon was a better person before he met her, and how Bamon was so much healthier and inspiring although at the time there was NO evidence in the show to support this argument. Everything the ship was based on at the time was purely theoretical.
But even the most hard-core Bamon shipper must have known deep down that their dream of Bamon ever becoming a reality some day was just that - a dream. The whole DE fandom knew that as long as Elena lived and breathed, Damon couldn't NOT love her. Maybe in an alternate universe, one where Elena Gilbert didn't exist - then Bamon might have a chance.

I know a lot of you have strong feelings about the possibility of Bamon actually happening after Nina leaves. I suppose it depends on what happens to Elena. Does she die? Does she leave town for a new life? Some of you might even argue that Bamon won't happen, because if it did, the writers would be making a giant mockery of Delena's love. You'd be right - there are major reasons why turning Bamon into a romance would be a terrible idea (I'll get to that later), but I don't think it depends on how popular DE are or how many people ship them - I think a lot of it depends on the producers and if they value Delena the way we do.

I don't know if any of you remember this, but in the past, Julie Plec has been a bit funny towards the DE fanbase on social media. link Sometimes I've wondered if she views us as a nuisance, and if that's true, she could 'reward' the Bamon fans for their loyalty, by giving them what they want. It's not unheard of for a show to cave to a fanbase's demands for a hook-up, particularly if a character is leaving, (like the Klaroline out-door sex); or if the show is ending anyway (Owen and Alex in 'Nikita'). I'm beginning to think Julie has manipulated the DE fanbase into thinking we would get a happy ending just so she could screw us over. She must have realised that DE was one of the ways to get people watching the show. But with Nina leaving, she has absolutely no obligation toward us anymore. In fact, her job just got much harder without Delena, which means she has to think of a new way to get people to watch, even if it means taking a huge risk and upsetting hordes of fans into the bargain.

If the producers were into Bamon from the start then they should have laid the foundations for it 3 seasons ago. Even when Bonnie didn't like Damon, there were things the writers could have done. A spell could have gone wrong, or something like in 'Buffy'. They could have been trapped in a basement together while a horde of werewolves or vengeful vampires lay in wait outside. The writers chose not to do that because it would have been too confusing for the love triangle. Viewers would have gone "Damon is supposed to be in love with Elena, but I don't know, he's very into that Bonnie chick."

The writers and producers have spent 6 years creating Delena's love story, longer than any other ship on the show. They made us think Damon could only ever love Elena. The list of famous DE quotes in which they pledge their love and how that love has had a life-changing impact on them is enormous. They made us believe that DE were meant to be, that they had a future together, and that future included spending the rest of eternity together. Even if they do a time jump into the future for S7, we're not going to just forget everything that happened. Damon spent the best part of 6 seasons loving Elena, and what, now she's gone, he's going to move onto her best friend Bonnie? What? How did that happen? If Bonnie was the best choice for Damon all along, why the heck did the writers spend so long on Delena? And why did it take Damon so long to finally see what was right in front of him? Is that really romantic, and doesn't he look kind of shallow and needy?
Not only would it be inconsistent story-telling, but it would probably cheapen the characters in question. Damon has told Elena how much he loves her dozens of times. And now we're supposed to believe he loves Bonnie just as much because Elena's not there anymore?
In an old song by Alanis Morissette called 'You Oughta Know' she sings about the betrayal she feels about her ex-boyfriend and his new girlfriend:

"And every time you speak her name
Does she know how you told me you'd hold me
Until you died, till you died
But you're still alive."

If Damon falls for Bonnie, doesn't it effectively render all his declarations of love for Elena completely meaningless? Wouldn't it feel like a betrayal? It would be extremely disrespectful and dishonourable towards DE if the writers make Bamon hook-up or turn them into a romance, because the writers would run the risk of making Damon look like he'd never truly loved Elena. He would look hypocritical, fickle, disloyal. Now, whenever you mention this to a Bamon shipper, they just bring up Katherine. Didn't Damon also fall in love with Katherine's doppelganger? Uh, yes...AFTER 145 YEARS! And Kat didn't even really love Damon anyway - not the way he loved her. OK, so Damon loved Kat, then after the passing of over a hundreds years, he fell in love with Elena...and then after he loses the great love of his life, he's going to fall in love with Bonnie too? Wouldn't it take at least 200-300 more years for him to get over Elena and meet another great love??
I don't expect though, that the writers will be that quick in putting the two together if it does happen. I predict they'll be more cunning than that. No, I see Julie paying homage to their "deep and profound" friendship in interviews, and saying that Damon and Bonnie will be "best friends that will change their lives forever." Then that 'friendship' will slowly segue into gazing into each other's eyes, and hand-holding, and hugging that lasts longer than is necessary. I hope I'm wrong. But if the writers want Damon to have a new love interest, creating a new character and trying to incorporate her into the story and crafting a believable romance - all in one season - could be tricky. I could also see Damon being alone, but everyone knows that ships bring in viewers and creates a buzz.

The problem is, after Elena leaves and DE is no more, there will be a big hole to fill in the story. I don't trust Julie Plec. Maybe I'm overreacting, or being silly and childish or whatever, but I feel like she's betrayed us. We've waited and believed in Delena for 6 long years. They made it very difficult for us to ship DE in that time. We deserve a happy ending. The whole DE fandom already feels betrayed that there'll be a seventh season without Elena. To replace Delena with Bamon would be even worse. Since Julie can never hope to capture viewers' hearts with Bamon in the same way, and because so many of us feel let down that Nina is leaving, it could well be that ratings for TVD bomb in S7. I once said in an article several years ago that the show began with Delena and it would end with them. In one way or another, that will be true.