Absolutely no. Zira is Vitani's biological mother. Any videos that show things like that or anything that has to do with a non-Disney character that isn't from the film is 100% fanmade. That's just made up by someone who believes in a different story line that filmmakers did not add to the film. Many fans believe some characters (especially those from outsider books 'TLK: SNA') that are NOT Disney creation, exist in the film rather than following the true canon.
Anyway, the cub in The Lion Guard is Kion but Kion isn't Fluffy. Fluffy will always be genderless or Kiara in the film alone. TLG is only a spin-off show for kiddies under 10 yrs plus, the show doesn't connect to the original film or the sequel. In the film Kiara will always be Simba's only cub. TLG is clearly not canon to TLK or TLK 2. But, still Official to Disney with a whole different story line.
Kion is Kiara's little brother only in the alternate movie universe, Disney already labled Fluffy and Kiara as one character and not turning Fluffy into someone else. Fluffy isn't anyone except Kiara. The creators of TLK 2 has clearly decided for Fluffy and Kiara to be the same. Kion is a newly character that only exist in TLG and TLG is not connected with the films. So, Fluffy is still Kiara in the two films and Kion is only a alternate character as Kiara's younger brother.
In a way, I'm glad that TLG isn't canon to TLK 2 because I seen it once and didn't like it. the animation is horrible and the voices aren't the same. Matthew Brodrick will always be Simba. TLG exists just to make money off of it. But then again, cartoons now in days are crap anyways. :P
