I don't see how 20 737 crews offset the 53 DC9 crews that will be displaced out of DTW on this AE. Also very unlikely any of those could hold 737 A or B (or 320 which is going to have FO MD's)

I get that it is likely to be a 365 conversion bid and that some might find their way to the DTW 717 on the next AE before training but many junior pilots will be subject to possibly two training cycles. The really junior FO's might have no where to go but ATL 717, but I see most DC9 A's MD'ing to WB FO rather than ATL 717A which will then waterfall displacements throughout the system as junior WB FO's MD into lower paying categories.

The only caveat I see to that is if the company decides to have a commensurate number of DTW WB vacancies or hold an excess in those categories.