I think there's still some potential places where more U-S/M info could be showcased:
-CoroCoro (Which, IIRC, still hasn't been leaked beyond the cover. Maybe more info on Dusk-Dog, like typing & abilities?)
-VGC Worlds 2017 (unlikely, but who knows?)
-GamesCom (seems most likely to me)

My guess is that there was a flood of info leading into S/M because it was a new generation, or perhaps it was following up on the campaign for OR/AS (where, IIRC, nothing was kept hidden for players to discover in-game).

There just seems to be too many mysteries at hand here. Though I do agree, more info would be welcome - albeit within reason, in order to have content for players to discover.

I also wonder if, since the US didn't get the Gen I VC Mew event, maybe we'll get both a Mew and Celebi event for the Gen II VC launch? And U-S/M should either permit any Pokemon with an origin marking (i.e. Gen VII, Gen VI, or Gen I & Gen II VC games) or make it easier to get HA legendaries that can be used on the Battle Spot.