Looks like they're freeing up B class. Tho no idea how it will be used.
Via
aasaleslink.com
Fare Class Removal – B Inventory
Updated: January 14, 2016
You are receiving this important notification to advise you we are removing B inventory from our fare class ladder. In the near future, we have plans to repurpose B inventory for the development of new sales products, which means any existing “B” fares will no longer be available for sale.
We have removed “B” class from our fare structure for all geographic regions. Bookings made up until January 14, 2016 will require ticketing in accordance with the fare rules or no later than March 31, 2016, whichever comes first.