The short answer to your first paragraph is that I don’t know of any communities for sharing short-form edited clips like that. A silly one like that might not be out of place somewhere like !animemes@ani.social.

As for AMV, sakuga compilations, and other general videos, they would be welcome in this community, we just haven’t had many people submitting them. Occasionally people submit videos of popular reviewers doing a seasonal rundown (e.g. Gigguk’s in a Nutshell videos). I also occasionally post 1-2 minute clips from shows (unedited). If we started to have a flood of video posts, then I might have to make rules about it, but it hasn’t been an issue yet.