I play for fun, within a quite busy daily schedule, so my availability is irregular. I try to always be available for a rematch when asked: if my time does not allow for it, apologies in advance.
I obviously lose about half of my games, and in that case I'm happy to congratulate the winner (not the standard behavior for some members of this site, I know). Obviously, if you disable chat when playing, I'll be less able to interact with you, including to discuss rematch availability.
To players who don't value displaying normal courtesy to others, I recommend: Consider either playing or resigning, in a losing position. Disconnecting and letting the clock run idle are poor form, and quite childish.
Enjoy your games.