Problem is that most of the guys that are holding ATL 767B will more than likely still be able to hold NYC7ERB. Ergo, because it pays the same they had the choice to bid that. Because they bid the 88B instead they will get 88 pay.
It is the most senior seat you can hold system wide not in base that counts.
FWIW, if you hold a line on the 88 you will more than likely make more money than reserve on the 767.
One guy I know is making over 1500 bucks more a months after taxes than a second year reserve 767 FO!