Anyways, people interested in becoming CAs/RAs don't receive their acceptance/declination until mid-December. However, the prime time for securing a good, desirable off-campus house/apartment is October-November. Thus, if someone applies for a position and gets denied, they could be stranded in a crappy apartment- a punishment considering they were trying to help the University.
So, I'd suggest starting the RA/CA application process earlier (notice of acceptance/denial could be in mid-October) so that prospective RAs/CAs could still secure desirable off-campus housing if denied.