If they really did that, then that's honestly a terrible change.People can no longer quit under 1 min to avoid point loss. That's pretty cool!
There are just often situations where quitting before 1min is, honestly, justified, and DE hasn't been making this much easier either: the lag in the past weeks has been frankly horrible(from one game with no issues to other where both players have massive issues to other where only one does); then you have also some potential game breaking bugs or some rare cases of known cheaters.
As long as being able to quit the game without losing ELO is a matter of being able to skip a potentially extremely unfun and uncompetitive game to be able to play a good and solid one, I think it should be very much allowed.
Though the arguably better alternative would obviously be to bring old save&exit back, where quitting the game without losing ELO was possible as long as both players consented