My suggestion is preview video. Consider that preview itself is a deprecated tag pointing to paid reward available or ad (also deprecated with a few alternative options, namely official ad aliased to promotional art implicated to official art). We don't have any tags with "preview" in the name and these are usually referred to as previews to begin with so I think it would be a good tag name.
At a high level, this tag is essentially just paid reward available + animated but you want a way to specifically filter out videos that are not "complete" so to speak. The thing is that most of these name suggestions are specifically focusing on a links advertisement end card but some videos that meet the criteria of what you want to filter (out) also just end abruptly instead of having a links end card, so those should probably be able to qualify as well.
I think preview video would be the best fitting tag name if we want this and it should be very difficult to avoid if the tag has a good enough name that allows it to be implicated to paid reward available to reduce blind tags. Freshblink brings up a good point, so ideally it should have a name that's good enough to imply it to paid reward available so it's even more abundantly clear what the tag is intended for.