Is this the video you saw ?
https://www.youtube.com/watch?v=NzWh6bXRt3E
Mentioned he’ll turn 5 years old next month.
That’s not the one I saw; the one I saw was a sort of news story/interview with the owners. But your video does seem to show Messi as rather smaller than a full-grown cougar should be.
This animal was like many rescues - probably would not have survived as ‘wild’ or ‘re-introduced’.
The ‘animal rights’ people are all about virtue-signalling, and possess little scientific knowledge and no common sense. They should be happy that Messi has a good home where he is loved and well-cared for, instead of being euthanized because he wasn’t ‘viable’.