Yep! That's B-101's way around not having a Christmas feed of their own. They have bought the Custom Channel package for a number of years now. In fact, that link is available all the time but isn't publicized until this time of year.
I'm still intrigued about B-101's Christmas song survey (you choose the songs) when they have already bought and are playing their Christmas music. Besides online, the signal is going over the air on B-101's HD2 broadcast channel.