The fact of the matter is, Vesperia's logo was in their announcement list. So was Galaga, Pacman, Pacman Party, and Tekken which have also been unaccounted for. Is there any evidence to suggest that they're done with announcing stuff? No.
The Twitter message of "Those weren't Vesperia logos, only massively warped TOGF images! I had to make a way to keep fans guessing." refers to the original images, and mentions absolutely nothing of Vesperia being in there. He's referring to the first two original images, he's just completely avoided the Vesperia logo being there to begin with. Of course, everyone thinks he's lying, and denying that there's a Vesperia logo.
They didn't do a very good job with the last image either. It's definitely Vesperia. I even photoshopped myself for re-assurance:

Graces is good news, don't get me wrong, but... I don't know why they would dick their fanbase like this.