At this point, I'm leaning toward the UBs not being obtainable. They're here more to be bosses, I think. I kinda hope we get to send out up to three mons at a time against them, to really nail down the feel of a JRPG boss fight.
Stealth Rock will also be pretty useful. Hope Lugarugan can learn it, as well as ancient power. It could certainly become a useful rock type pokemon.
They showed a battle royale at Gamescom where a Rockruff got used at one point, and it had Stealth Rock in its moveset. That's a guarantee that at least the day form can chip off some of an opponent's health when they switch in, then maul them with priority STAB. If this line can learn Swords Dance,
look out.
In related news, the trailer on the 20th is probably where we'll get the localized names, typings, and the lore on the site. Sandyghast and Palossand started out as "Corocoro exclusives" in the middle of the month, but then their official reveals came at the PWT, only a few days after the magazine officially released. This'll likely be something similar.