The gym leaders, badge names, TM rewards, and the Pokemon they each have has leaked. Not confirmed, but feels pretty legit. You’ll see names of some unreleased Pokemon as well as some potential Galarian forms.
For those not wanting to click the link:
Gym 1: A Fire-type gym led by Kabu who uses a Growlithe and Inferver. Rewards the Steam Badge and TM59: Incinerate.
Gym 2: A Grass-type gym led by Milo who uses a Pumpkaboo and Eldegoss. Rewards the Harvest Badge and TM86: Grass Knot.
Gym 3: A Water-type Gym led by Nessa who uses a Barrazucca, Chinchou, and Drednaw. Rewards the Tide Badge and TM96: Aqua Jet.
Gym 4 (Exclusive to Sword): A Fairy-type Gym led by Opal who uses a Shiinotic, Parasect, and Impidus. Rewards the Sprite Badge and TM77: Scuffle.
Gym 4 (Exclusive to Shield): A Poison-type Gym led by Sopp who uses a Foongus, Smudgsqueek, and Weezing. Rewards the Spore Badge and TM06: Venoshock.
Gym 5 (Exclusive to Sword): A Fighting-type Gym led by Bea who uses a Hitmontop, Sirfetch’d, and Grabble. Rewards the Grapple Badge and TM31: Brick Break.
Gym 5 (Exclusive to Shield): A Ghost-type Gym led by Allister who uses a Mimikyu, Polteageist, and Purugly. Rewards the Spirit Badge and TM30: Shadow Ball.
Gym 6: A Dragon-type Gym led by George who uses a Drampa, Dragonair, Duraldon, and Anisgon. Rewards the Folk Badge and TM67: Dragon’s Roar.
Gym 7 (Exclusive to Sword): A Dark-type Gym led by Donnie who uses a Mightyena, Obstagoon, Weavile, and Troublin. Rewards the Eclipse Badge and TM59: Brutal Swing.
Gym 7 (Exclusive to Shield): An Ice-type Gym led by Niklas who uses a Grumpig, Mamoswine, Snonolith, and Frostilla. Rewards the Peak Badge and TM70: Aurora Veil.
Gym 8: A Steel-type Gym led by Wesley who uses a Steelix, Klang, Clautant, Persian, and Mechanos. Rewards the Sheen Badge and TM91: Flash Cannon.