Personal thoughts/opinions (ex-Eagle, current JB):

-9 gates at DFW is way more than JB could make use of
-The 190 at JB is being pulled from most routes ~800nm+ because of poor performance (DFW-BOS/JFK/FLL/MCO are all 800+)
-We have been hearing rumors of DFW service at JB, but that would most likely be a token amount of A320 DFW-BOS/JFK flights (2-3x daily each)
-APA would flip their lid if Eagle started flying E190s

Conclusion:

AMR/AA is setting up to eventually get 100seaters in AA colors, operated by APA pilots. JB has been trying to get rid of future E190 deliveries, so I wouldnt be surprised if they worked out a sweetheart deal with AA for those planes. Also dont forget this article is just describing some blueprints that are a very early stage of the planning process. The AA terminal in JFK was originally planned to have a huge wing that would be exclusively for Eagle. Needless to say that never happened and Eagle operates out of an afterthought of a jetbridge setup.