That video isn't describing something that's Canon to the film trilogy so, no? And as far as the other things you said, there's nothing in the films to indicate that, so it would just be a theory. All this stuff has already been talked about in other threads on this forum in length, if you want to explore around the TLK2 sub-forum tho.
viewtopic.php?f=32&t=51888Here's a good topic to read on about it. As described in the film, Vitani and Nuka are considered direct heirs of Scar, and Kovu in the script was an illegitimate heir of Scar, but was changed in the film in order to make it to where he was the hand-picked heir. Whether he's Zira's son or not is kinda up for debate, but according to the movie he wouldn't be.