Based on the leaks and current episodes, Ash's pokemon seen so far and expected to debut;
Ep 1: Sceptile, Donphan, Buizel, Noviern, Mr. Mime
Ep2: Leavanny, Totodile, Corphish, Rowlet
Ep 3: None
Ep 4: Incineroar, Snorlax, Talonflame, Oshawott
Ep 5: Squirtle, Charizard, Bulbasaur
Ep 6: Snivy
Ep 7: Kingler, Lapras, Sirfetch'd, Bayleef, Torterra, Heracross
Ep 8: Gengar (hopefully more)
Not seen yet:
Oak Pokemon:
Dracovish, Tauros, Muk, Pignite, Quilava, Torkaol, Infernape, Primeape, Dragonite, Hawlucha, Lucario, Gible, Noctowl, Palpitoad, Gliscor, Unfezant, Scraggy, Krokodile, Staraptor, Swellow, Glalie, Boldore
Released:
Larvitar, Primeape, Goodra, Butterfree, Amibipom, Pigeot, Naganedel, Greninja
Pokemon with Kukui and roaming in Alola:
Melmetal, Lycanroc, Solgaleo
Hopefull we get more leaks. They way I can see this working is, episode 9 and 10 featuring a full team or mid team. Then episode 11 featuring the leftover reserves at Oak's Lab and a ending montage of Ash revisiting his released Pokemon.