Normal: Whitney and Norman. Since there was a generation gap, maybe.
Fire: Blaine, Flannery. Possibly a Fire gym this gen, to keep the pattern going, lol.
Water: Misty, Wallace/Juan, Wake. No Water this gen.
Grass: Erika, Gardenia. No Grass this gen since we had one the Gen before.
Electric: Volkner came last gen, and we've also had Surge and Wattson. No.
Ground: Giovanni was the only Ground, we need another one.
Rock: 3 Rock Gyms before (Brock, Roxanne, and Roark). No.
Ice: Pryce and Candice, even though the latter was last gen, Ice is in the minority, so that's a maybe.
Fighting: Chuck, Brawly, and Maylene. No.
Psychic: Sabrina, Tate & Liza. Why not, keep the same pattern that Fire had going with Psychic as well.
Dark: No Dark Gym? Definite yes.
Ghost: Morty and Fantina. It's in the minority, so maybe.
Steel: Bryon and Jasmine. Yes.
Dragon: Clair was the only one, so yeah.
Poison: Koga and Janine, who were both for Kanto. WAY PAST DUE.
Bug: Only Bugsy, and that was 3 gens ago, yes.
Flying: Winona and Falkner. Hmm...Generation gap, sure.
Normal, Fire, Ground, Ice, Dark, Ghost, Flying, Bug, Poison, Dragon are all possibilities.