Decidueye is the second coming of Hoopa, immune to both GX and V. Definitely going to be a very annoying deck for certain archetypes.
Dracovish can auto-win against certain decks, but Boss's Orders turns it off, giving them a chance to evolve... mmmm, it may warrant some experimentation tho.
Mimikyu prevents healing from bench, and Mr Mime prevents scooping up; these two combined with Dragapult V-Max would be annoying AF to face, it's unfortunate that Dragapult will probably go the way of the dodo once Eternatus releases.
Salamence V-Max hits hards and that's about it... Strong Colorless + TAE + Vitality Band makes you hit for 270, which is probably good enough for its own deck, but it also has a really unfortunate weakness.
+50 HP tool for all basics except GX mons... certainly an interesting tool for the right deck.
Birdkeeper is the second coming of Tate & Liza, except it has both effects combined - I bet some decks will appreciate the extra copies of Switch that can be recycled by Cynthia & Caitlin/Pal Pad.
Scizor V-Max just doesn't have the damage output to make it a concern - 90 + 30 damage reduction is honestly weaksauce.
I already mentioned Strong Colorless, but I'm having trouble finding targets that are powerful enough to appreciate the extra +20 damage and are also easy to load...
Why does Flygon keep getting cards that are on the verge of being good, except held back by being stage 2?