Sounds like what I've experienced over the years. If your flight is cancelled and the new flight doesn't have BS, they'll give you a refund for the difference between the anytime fare and BS fare.
It's tricky when they swap planes after everyone is loaded up. This happened to me a couple weeks back at MDW, and the GA said "this is an honor system, folks. I can see your BP numbers, so none of you Cs try to board with As." It worked and folks were generally in the same place. They even took the same seats (except the man with the screaming baby who sat across from me instead of row 24 like he originally did).
Originally Posted by
Nevada1K
Personally, if my confirmed flight is cancelled, I consider myself lucky if I can get on the next flight and I don't worry much about my boarding pass number/seat selection.
+1