If Kopa was in the TLK || then what would happen to Kovu since two male lions can't be in the same pride?

If Kopa - or any son of Simba and Nala - was in the story, I don't think they'd written Kovu in it at all. After all the most basic point of Kovu is that he falls in love with SImba's daughter after he joins SImba's pride, so that he could become who he can be instead of who his mother was trying to make him.

So what would happen to Kovu if Simba has a son in the sequel?
My answer simply put: Kovu wouldn't exsist in the first place and the story would be perhaps entirely different from what it is now.

But that's only for the story matters.
Because lion prides have one or two LEADER males, but it doesn't mean there wouldn't be more males in general. A lion pride may have even 6 males. So in that sense Kovu wouldn't necessarely be a problem. But just for the matter of the story Disney wanted to tell.

I'm not sure, but I consider Kiara would be the older one, so
Kovu might still be next in line to be king, since he's Kiara's
mate, If something happened to Kovu disease or he was killed then Kopa might take over as king. But other than that, Kovu is the future king.There are two to three lions that can rule one pride.

simba is a laid back father they probly could live together