They do. You’ll see a lot of hate for DLSS on social media, but if you go to the forums or any newly-released game that doesn’t have DLSS, you’ll find at least one post demanding that they implement it. If it’s on by default, most people don’t ever touch that setting and they’re fine with it.

They shouldn’t, but since the game has been enhanced, there’s a good chance that something will go a little wrong and need a patch. I would actually guess that most of them end up with a patch, but only a few end up with game-breaking bugs and need a patch.