Supply and Demand. That's what it is all about. I think this kind of thing is going to happen more.
Yes. Usually it is the other way, pro shops can't get rid of them, so they must sell bowling balls at reduced prices to make room for the new stuff. However, with this whole concept of "Ball of the Month", manufacturers probably don't produce as many bowling balls as they used to. Most bowling balls have a very short shelf life.
Be prepared, if the ball is really good and no longer produced you are probably going to pay MSRP or more.