Changes my habits, too
My partner and I also typically book into the higher/refundable coach fare buckets, but with this change, we are unlikely to continue doing so. It's a very foolish business move on DL's part, as it's going to DECREASE, not increase, the money I spend with them.
Each of these moves teaches me to put less and less stock in airline loyalty programs these days, and more into perhaps just bargain-hunting across all airlines. Perhaps we should just abandon the loyalty and elite games.