Most of the times the only valid reason for a seller to upload the video they made would be so that they can showcase it in their portfolio.
But even then the seller needs to get permission to do so.
Copyright is a tricky subject.
I own and maintain copyright for the actual source files of every project I make as it is my own IP. I license it to the client.
They own the end video file but not the design if that makes sense.
However no video animation seller should have the option to charge more for “copyrights”. We can charge more to deliver source files. But no video animation gig would ever ask for copyright fees much like VO artists do.
That’s a whole different thing and one I occasionally have a problem with. Bit that’s for another topic.
@eoinfinnegan the buyer was very specific when they said they dislike the fact that the seller is getting more exposure using the same video. But we have no context.
Where did the seller upload the video? Did they ask permission? Do they own a larger channel and therefore are getting more exposure? Was it a video the buyer was hoping to monetize?