I really believe that this will be the case, along with Pac-Man, and possibly a third newcomer as well. Everything's just lining up perfectly.
Last E3, two characters were revealed in the E3 Nintendo Direct; one (Villager) from a series that had its latest localized installment (Animal Crossing: New Leaf) releasing during the same week as E3, and a third-party character (Mega Man). Additionally, a third, completely unexpected newcomer (Wii Fit Trainer) was revealed later on in the day.
Fast forward to this year's E3. Yet again, we have another localized game release during the week of E3Tomodachi Life. And what does Tomodachi Life star? That's right, Mii characters! And it would make sense to have a second third-party character reveal along with Mii, too, and who better than Pac-Man? They're both from the original Gematsu rumor as well. They're the last two character that have yet to be revealed from that supposed leak, in fact. On top of that, we could maybe get a third, unexpected newcomer à la Wii Fit Trainer. Maybe a Rhythm Heaven character like Chorus Kids/Marshall (from the second Gematsu rumor)?
It makes too much sense!