If they can make it so the system detects a server issue versus an intentional disconnect, then that would be an improvement. But sketchy internet at home disconnecting you? That’s on you. Otherwise there’s nothing to stop those quitters from just turning off their router or whatever to preserve their rank.
And it 100% should not apply to anything but Ranked - though that said, I’ve had just about enough of people dropping out of Horde groups (AFTER the lobby). And it should never apply to quitting out of a lobby either - only once in game.
Aside from that, I’m all for two year bans for people who quit 18 of 21 matches in a day. But I also agree with their decision to rescind the bans with a warning once. Now everyone is aware of the consequences, and there’s no excuses.