The link you sent titles the video “Zelenskiy threatens to come for the children of Crimea”. What he says is that they’re going to retake the Crimea, and while the video starts mid-sentence he seems to be saying that children who have grown up in occupied Crimea have been exposed to Russian propaganda, which I’m sure is true. The International Criminal Court has been issuing arrest warrants for people involved in a Russian program to abduct Ukrainian children, FYI. So getting the minds of the next generation is demonstrable part of the Russian war strategy. In this clip, it seems like he’s responding to a direct question from a journalist. While I doubt Ukraine will ever retake Crimea (and tbh I think Russia has a pretty solid claim to it), I understand why he’s saying they’ll retake it, and none of this seems like strange thing for a wartime president to say. Overall this seems like a pretty clear case of disinformation promoted on an app run by a fascist.

For the Azov point, you can just read the Wikipedia article on the Battle of Mariupol, or there’s a Kyiv Post piece here. It does seem that components of Azov have reformed but they’re far from what they were.