The way I see it is leaks are getting leases and less a trustworthy as time goes on. People get more and more hyped, want answers, or are just simply impatient. Trolls and attention seekers take advantage of that and they make fake leaks. I doubt Nintendo would let people they weren't sure they could trust work on major things like characters. Sakurai wouldn't want his reveals to be ruined. Megaman, Pacman, Littlemac, etc. generated extreme hype. If the Gematsu leak was even real it was information from extremely early in development, and it isn't trustworthy anymore. The leak did have some extremely hyped characters, but it didn't have new mechanics, game modes or anything else major. Sakurai wants certain things kept secret, and most likely anyone who would leak anything major doesn't know about any things major in the first place. Sakurai wants to keep Ridley a secret until his reveal, and I'm sure there's more characters like that. Any leak involving Ridley is mot likely fake, but Ridley is still probably a character.