Release dates:
Isle of Armour: June 20th.
Crown Tundra: November 13th.
Galarian Forms(don't know which are in which pack):
Slowbro: Poision/Psychic
Slowking: Ghost/Psychic
Blitzle/Zebstrika: Water
Tentacool: Ice
New evo named Tentagool: Ice/Poison
Phanphy: Rock/Fighting
New evo, don't know the name, but it's also Rock/Fighting
Smoochum/Jynx: Water/Fairy
New evo, don't know what it's called, but it's also water/fairy, and it's a mermaid with shells on it.
Dustox: Poison/Flying (Klara's ace)
Beautifly: Psychic/Bug (Avery's ace)
Aipom/Ambipom: Fighting
Mareep/Flaffy/Ampharos: Fairy/Electric
Poochyena/Mightyena: Fairy/Fighting
Seviper: Psychic
Zangoose: Poison
Articuno: Ice/Psychic
Zapdos: Electric/Ground
Moltres: Fire/Dark
Golduck evolves into Minduck, it's Water/Psychic.

Calyrex's gmax form looks like a giant flower.
I haven't seen many gmax forms, but I saw Salamance(looks like a flying king dragon), and Palossand(looks like the Taj Mahal).
New Regis:
Regidrake: Dragon
Regibolt: Electric

Lot's of Sinnoh refrences in the Crown Tundra, to tie into next years Sinnoh remakes(Time Diamond and Space Pearl), including Professor Rowan making an appearance, to talk about how dynamax is also possible in Sinnoh.
Regigigas not in the dlc, because you have to transfer the 5 regis over to the Sinnoh remakes to get Regigigas.
Kurt is on the Isle of Armor to make apricorn balls.
There will not be a third dlc pack.

Not a direct, but a long trailer coming early June to talk about the dlc, and it will show a teaser for the D/P remakes at the end.