Sold Out convention doesn’t mean a sold out hotel as convention sizes vary. The conventions contract for X number of rooms way ahead of time. If Disney needs to walk you for some reason generally they call before you arrive. Disney will not mention anything to you about a convention you are not part of.
Lessons I’ve learned from conventions at CSR during my hotel stay
-Make dining reservations for non-QS planned resort dining now, even if you just want to hit Rix
-The bars might be busier than usual
-There could be elevator backups in the Tower so leave some extra time
-The DS bus can see higher demand in the evening so leave extra time
-If you need to visit the front desk be ready for a long wait or try at odd hours like late at night (I had the bad luck to need to visit on check-out day and my check-out day coincided with a line like 50 people deep from a convention also checking out).