I'm surprised they actually emulated the old Compass holdover policy. The purpose of it then was to protect Compass from shutting down from losing too many pilots too fast whenever hiring started up at an unknown time in the future so they could catch up to their training and hiring. It was supposed to be a temporary stop gap so they could get ahead of the curve, but instead they simply planned on it to keep staffing at bare bones and let DL eat 3 months of lost first year pay on that side of the ledger. Compass was tiny compared to EDV (about one fifth the size of EDV today) so it kind of made sense there as a temporary provision. How it came to be a permanant feature at an airline 5 times its size just goes to show how desperate regionals are to "optimize" staffing down to the penny. Why DL doesn't force them to hire a few dozen extra pilots one time to get ahead of the well known curve is baffling.