It gets to be way harder to argue in court when it isn't a "clean kill", using Ross Scott's words, so The Crew is going to be one of the best examples we'll ever get for courts to rule on. I expect Ubisoft would rather settle than let this one go that far though.

I imagine a lawsuit would likely bring up the topic of how hard it would be for a developer to keep the game around past purchase.

For instance, imagine a massively multiplayer online game; everyone playing the game is acutely aware of how much server hardware is needed to maintain that online presence, and it's unrealistic to assume it would exist forever.

That's probably why attention was pushed onto The Crew. It's a racing game that shouldn't need much from a server, so it's arguably unfair to tie it to that access and take it offline.