They’ll be forced to accept it, at least in the EU, they will also need to enable you to resell your games. EU law on this is clear, rulings in other cases are clear, all we’re waiting for is for Valve to stop appealing or lose before the ECJ, whatever is first.

The tl;dr is if they want to argue that they’re simply renting out licenses then they shouldn’t be taking one-time but regular payments, or only give out time-limited licenses for one-time payments, or some such. They should also avoid terms such as “buy” and “summer sale” like the plague.