MAN's strength has been its diverse portfolio of airlines. I love all that TCX have been doing and to be clear I am not "blaming" them at all.
AA clearly have certain issues at JFK and TCX have ruthlessly exploited them on the MAN route.
I hope the reaction to this from VS and UA is positive, and they seek to increase their market share. From AAs perspective, I hope this strengthens ORD and PHL. However, I am concerned that this might be the start of a long term trend of TCX taking over - which would not be good for the consumer in the long run.