I have 6 receivers on my account already, including 1 9242. I imagine they will try and give the replacement 9242s to the custumers who already have 6 on their account.
UPDATE: I just got off the phone with Bell.. I have two receivers to be replaced, a 9242 and a 6100. He said that since we already have 6 receivers on our account, if we didn't end up getting a 9242 in the swap they would most likely make an exception and allow a 7th (this isn't official, just what he told me). I actually don't mind if we don't get a 9242. We do use the 2nd tuner out, but I could make it work with the free 5900..