This is the first time that a fully fledged Forza Motorsport game is coming to PC as well as Xbox, so it's a fair question to ask whether cross-play is supported.
Here's how the feature works, along with what else transfers from Xbox to PC and vice versa.
Forza Motorsport Cross-Play
Forza Motorsport fully supports cross-play! Users across Xbox Series X|S and PC can play together on both platforms.
Forza Motorsport Cross-Save
The new Forza Motorsport also supports cross-save. You can carry on your progression seamlessly on Xbox and PC - including with the Steam version!
Xbox achievements are also shared across the console and PC versions of the game.
"With cross-play for online matchmaking and cross-save, you can play with your friends across PC and console and for the first time, continue your racing journey across Xbox Series X|S and Steam with shared progression and achievement unlocks."
Happy cross-play racing!