While this would be great for those "online needed to play" games, wouldn't this also lead to companies preferring subscription models?
I'd assume it's easier to not include multiplayer in the "base" game and just charge a monthly subscription for the online part. Now the proposed law wouldn't apply, since the customer only paid for the base game.
It's pretty obvious what the intention of the writers of the proposal is, but I feel like it could have an opposite effect and push even more to the "games as a service" model those greedy publishers so desperately want.
The problem is that a lot of companies are already launching dead-on-arrival live service games, so unless they're willing to make something unique, all they will do is saturate the market further and keep burning money. I don't think this law would change those incentives much if at all.