I'd be shocked if release isn't on November 22nd. That follows the last few release trends, being the Friday a week before Black Friday. I also agree that we'll likely get the cover legendaries next. I have to think that, whatever we get next, will come alongside the box's cover art. As such, seeing legendaries (or whatever they show on the box art if they feel like changing it up) would be no surprise.
I'm definitely getting ready to see the next reveals. I was surprised by how much we got in February after SM's reveal gave us next to nothing, so that has left me satisfied for a while now; however, it does feel like about time to see some new stuff. I'd assume we'll still get something before E3 just to whet out appetites. Looking back to last year, Let's Go: Pikachu/Eevee's reveal was on the 29th of May and had a spot at E3. Traditionally, Pokemon is not the headliner, and I don't see that changing this year. I think that will go toward Animal Crossing (their probable big holiday title) or Mario Maker 2 if they want to give it the biggest push possible before release. Even if SwSh isn't the biggest thing on the show floor, it'll almost certainly have a presence. I still think back to X/Y's big session outside of the Direct or S/M's segment on Treehouse Live as better than if we had just gotten a trailer in the Direct. If I recall, they did a similar Treehouse segment on Let's Go too. I imagine, then, that SwSh will be spotlighted in a similar fashion. Heck, if S/M could interrupt the near-endless stream of BotW in 2016, they'll definitely show off some SwSh this year.