Well, the contract can’t break the EU consumer laws if it’s sold in EU countries. The whole debacle with Ubisoft shutting down The Crew a year ago sparked a Stop Killing Games movement, which can further push things in favor of the consumers.
Regarding downgrading - recently I wanted to downgrade or rather download earlier version - you can do that with dcs_updater, pretty old build (like 1.2 and 1.5) - is not available, I think the last supported version might be somwhere around 2.5.x