SEGA has confirmed that cross-platform play is supported on the Sonic Racing CrossWorlds open network test and in the main game in general. This means that you can play with your friends online even if they are on other consoles. The Sonic Racing CrossWorlds open network test kicks off on Friday.
Sonic Racing: CrossWorlds supports cross-platform matchmaking, even on network test

Neato. I’m glad it supports crossplay.
Yup. I wonder is joker playable normally?
We knew that already 😒 since like the summer game fest trailer.