https://wccftech.com/ubisoft-plus-could-be-added-to-xbox-game-pass-ultimate-says-jeff-grubb/

Ubisoft Plus, the rebranded UPlay + subscription service, is currently only available on PC and cloud streaming services like Amazon Luna and Google Stadia.

However, VentureBeat's Jeff Grubb is confident that Microsoft is trying to work out a deal to bring Ubisoft Plus on top of its own Xbox Game Pass Ultimate subscription, which would add it to Xbox consoles as well. There's precedent for that, given the recent addition of EA Play on Xbox Game Pass.