I was kinda wondering about that with the 737, they really have stretched that design to the limit...and were resisting the redesign of the box, with all the the engineering going into the 87.
The success of the NEO drove them to do this, and the potential to lose a much larger portion of the AAL contract, short squeeze is a good term...
Airbus may have to open that facility in the US after all....
(Boeing knows how to build airplanes, they do not know how to make money building airplanes)