I read the FAQ's and i didn't see an answer, so if I missed it I apologize in advance. It seems like a dumb question already

I'm not flying the outbound half of my upcoming trip because it was decided.. 8 minutes ago.. I was flying out tomorrow instead and using someone's reward ticket rather then paying to upgrade my ticket to the higher last minute fare.

I know I can just let the outbound go by and the money will be able to be used toward a future flight and southwest being super-nice wont cancel my return or anything - but shouldn't I be politely canceling or something, like if someone else is trying to get that flight?

Not hogging up the space I definitely wont use?

I know, airlines overbook and it's probably not even a full flight, but i know i'd appreciate it if a flight was booked up and i need to get on it for some reason. Does it really just not matter?