I was against a new type at first, but the idea of a fairy type got me intrerested. The leak information may be sketchy, but I do believe in it nonetheless and of course the Pokemon Smash thing. No skin off my bones if it all turns out to be fake and there is no fairy type, but I would welcome it with open arms.
I definitely believe in the existence of a new type, but I'm slightly less confident about it being specifically called Fairy. It's definitely becoming hard to ignore, and when you take all of Sylveon's different-language names into account (particularly the German one that includes their word for fairy), a Fairy type just seems like one of those things that will be obvious in hindsight.