Delta rarely, if ever, over-fills vacancies on an AE (do you have an example, cause I can't think of one). Understand that if they post 10 vacancies, and 20 people bid in, and 10 people bid out, that isn't over-filling, that is just filling.

Delta almost always has a number of categories with open vacancies after an AE. If they post 500 new seats, with the exception of a few categories where they choose not to backfill, you will have close to 500 seats available after the AE. It is a net sum gain. Those seats are filled with new hires, future AE's, or adjusting the category downward. It is by no means absolute, but having watched it the last couple years, it is as good as any as far as a predictor of where the company will focus new hires for the next couple months (until the next AE.)