I suppose anything is possible. But going from "I've never heard of this character before" to "This is now one of my most wanted characters!" in the span of a few weeks seems like a fairly artificial progression.
Well obviously. Every character has SOMEBODY asking for them. I myself wanted Hayabusa before Hayabusa showed up in leaks. But it's pretty obvious what kinds of fans these new people are.
That's my point though, those character's AREN'T who they actually want. They're just posers trying to get more checks on their wishlist.
For someone who has OVER 30 characters you claim to care about, it's odd that you'd be so skeptical about other people's love for characters.
There is some truth that leaks increase characters possibilities. I myself had never heard of Doomguy until the Google Theory. But, after hearing about him I played Doom and found it was one of my favorite games in a long time, spoke to me on a deep level lol.
Thus I've only become a Doom Slayer supporter because of leaks, but that doesn't mean my desire for him to be in the game is artificial. I just think it'd be sick as all heck to see him rip and tear in Smash.
I also don't give a hoot about Reimu, Kos-mos, Hayabusa, or Lloyd, even after they've been leaked. I feel like most people operate the same way, where they learn about a character or game through leaks, then realize they like the game afterwards, adding one leaked character to the list while ignoring the others.
Also, some people are putting characters to please fanbases in addition to their own desires, so I guess you're right that they don't really want them, but you're right for the wrong reasons I think.