I agree. That one 5chan post made sense of a lot of things especially "third parties don't want their characters to be just Smash characters." We've been asking ourselves since last spring when the SMRPG remake/remaster/rumor was still a Star Road secret if Square would hold off on Geno until the announcement of that and that post reminded me of those conversations. The answer is "Mmmmm, yeah..." If Hero was theoretically withheld from the base game to be released closer to the release of DQ XI S, I can definitely entertain Geno being withheld but the Mii costume being released just for the sake of completion/profit. Also, a thought that kind of made me grimace at work today: releasing the Geno Mii with an actual Geno would be kind of a dumb idea. If you wanted to get maximum profit from the Mii costume, release it first because most of fanbase would feel compelled to buy it because they want a consolation prize. Release them together and a vast majority of people are just going to skip out on it.
screaming from the distance: "I'VE BEEN ARGUING THIS FOR MONTHS, YOU TWO TON ****!")
Of course, the rub is whether the SMRPG remake/remaster/sequel is real or not. If it yes, yeah... I could totally see Square and Nintendo pulling an Isabelle/Hero to promote it.