Looking at Black and White's release, which Sun and Moon so far seems the closest to (Magearna being the first new Pokemon revealed around the same time as Zorua and Zoroark, the titles and logos announced a bit later with no further info, first CoroCoro coverage in April)...
Guessing the main thing we'll see this month, if anything, is a few generic shots showing off the game's graphics (and how much they've changed since XY) including the starting town, the battle system, a random area, and whatever big Hawaiian (?) city that will serve as this Gen's Castelia/Lumiose that the budget is poured into. Also probably an in-game shot of Magearna, and probably Sugimori art + stats to go with it. That leaked April 10th for Black and White...I recall the earliest I've seen with CoroCoro is the 8th.