There's gotta to be a little growth. This order was for 460 aircraft plus options. The entire MD-80, 757, and 767-200 fleet stand at 364 aircraft. A320s and 737s won't be doing the super long South America and Trans Atlantic 757 flights.
American still has the issue of the ERJs, what will replace those? I'm hoping they are replaced with C-Series or E-195s flown by American pilots. It obviously won't be a 1:1 replacement but there should be space for 100 to replace part of the ERJ fleet. Maybe a deal struck for 100+ seaters at AA for new ATRs at Eagle to replace the rest of the ERJs? I'd like to see the CRJ-700s at American but I'm not sure AMR would go for that.