It is what it is. I don’t see the video clips as spoilers. First, for fanedits, those that download them are supposed to own the source material. So those that get the edits should already own the movies. Without context, those clips should mean absolutely nothing to anyone that is watching the movies for the first time. I assume that no one watches trailers for movies then since those include spoilers. To me, that isn’t a valid argument.
But I’m not going to tick anyone off by ruining their experience of the movies. I’ll just leave the old intros on and be done with it. I wanted something special for the new releases, but that just isn’t what is wanted.