When hearing back from a lender it depends on the lender and the situation. Here is a link to their policies: https://www7.bankofamerica.com/home-loans/learning-center/ho
Based on my experience with REO's, lenders do order new BPO's when the old ones expire.
One thing you may be dealing with, it went from a short sale to a bank owned house, meaning the foreclosure process in your state is over. The bank has taken possession of the house, which sends it to a different department within the bank. Keep looking at it, they may list it with a realtor. Your realtor may be able to help you with this part, but remember the realtor may be just as much in the dark as you are through no fault of their own.