I don't think they'd dedicate a Nintendo Direct to an already-announced game just to announce a few Pokémon. It'll be something bigger than that.
And as I keep pointing out, the official reveal for starter evos in the last two generations didn't come until either just before (fifth) or just after (fourth) the games' releases. We still have over a month to go. I wouldn't count on them even appearing, much less being the focus.
Creator of Jay's Journey (see quote!) "It's not ten years old! Therefore, it sucks!" - Nostalgia whores everywhere