The warning clearly states that the games won't be accessible on Steam from September 1st, 2022. Currently, there is no information if the owners of Ubisoft Connect versions will also lose access to their games.
Do you think Ubisoft can pull a stunt like this? Gamers have never encountered a situation in which a single-player game became unplayable after delisting it from the storefront.
Yohoho, mf.
Given that they're removing it from the storefront you can probably appeal to Steam support and get it refunded anyway.