In the past, I've wanted to purchase a B fare and upgrade with miles to WBC. The problem however, is that often the upgrade seat wasn't available when I had to make a decision on what fare class to buy. Do you buy the more expensive B fare class hoping that maybe the upgrade seat would open up later? Yes, I did that because at a minimum, I knew I would at least get 150% EQM's in case that upgrade seat never became available later.

Now with this change, my incentive to buy the B fare class is gone. Dumb move Delta!