Yeah, I definitely didn't speak to every single person individually at my wedding, including people I don't see that often and would have *liked* to speak to. Because there were a lot of people and limited time and a lot going on! I didn't do that on purpose, I just didn't manage to catch everyone. Even a fairly chill wedding, like mine was, is a bit of a whirl. It happens!
Plus I would not be at all surprised if Dad's siblings weren't top priority because, frankly, they sound like arseholes.