Cross-play should come to Watch Dogs Legion's online multiplayer.
Ubisoft has confirmed this via Twitter. A response informs that the developer is currently working on implementing the option so that players can play with each other in the game regardless of platform. This also involves cross-generation play, so it doesn’t matter which generation of consoles you play on. Cross-play should be added to Watch Dogs Legion with a future update, but Ubisoft hasn’t given a time frame for now.
While crossplay and cross-generation-play is currently not available for the Watch Dogs: Legion Online Mode, the development team is working on adding this feature to the game with a later update.
— Watch Dogs: Legion (@watchdogsgame) March 14, 2021
Last week, Watch Dogs Legion online multiplayer was added to the game on consoles and Stadia. Online multiplayer will be released on PC at a later date.