At American, Piedmont is consolidated into Envoy who will fly small and large Embraers.
PSA will fly the Bombardiers and Skywest, Republic and Mesa will be left with Gojet and Compass flying absorbed.
There is no benefit for AA to consolidate Piedmont into Envoy; the manpower required to staff the flying is pretty much the same regardless of who does it since there is no real overlap in bases to lead to a crew benefit.
Also, by keeping Piedmont around; it gives AA something to pit against Envoy pilots when it comes to negotiating pay and # of small RJs.
Also, you reference GoJet; GoJet doesn't fly for AA at all.
I'd also say that Mesa will probably end up being shown the door at AA. The CR9 contract for the LUS birds should expire sometime next year as I recall and Mesa's performance is subpar on both the on-time performance front as well as a customer experience side (broken seats, inop APUs, unhappy crews, etc.) Those CR9s would likely be replaced by a combo of E75s (from the Envoy front in DFW) and CR9s (from OO, replaced by E175s at DL).