My personal opinion is that it won't move. There's too much invested, too much involved in the marketing of a regional bills team that they would need to start over with. Not only that, Russ Brandon went to Fisher and is an active alumni. I actually graduated the same year as him, I think, but didn't really know him. Ralph Wilson also has some investment in Fisher, so I'm not sure he would want to move either.
There's no way it would move back to Buffalo. It wouldn't make sense.