Here's the top reason they list for needing the flow up program:

EtD Commitment is expected to bolster Endeavor’s ability to attract career-minded pilots while positioning the airline for growth.

Delta wants to make sure Endeavor has the capability to grow. Are you guys sure it isn't worth some negotiating capital to continue shrinking the number of large RJs?

Face it, they still love the 70-76-90 seaters and will do whatever it takes to breathe life into the struggling regional model. I see this as a very creative way of helping ensure Endeavor is able to retain the staffing required to continue flying routes that Delta pilots should be flying.