Well, this should really be a question for them, which is quite difficult to begin with, considering they don't have a forum.
I don't have any idea of their motivations, if someone announced any scenery and is realistically close to release (meaning, not simply put the scenery in a to-do list that might never be completed), we'd consider that one as off limits.
Sometimes there is some communication between developers in order not to do the same thing. We surely talk with FlyTampa and Aerosoft about their/our upcoming projects, even if sometimes funny things happens, like in the case Hong Kong: we knew for a long time that FlyTampa was working on that one, but since they only told us "we are doing Hong Kong", we were convinced it was the other one...
But, apart for these mishaps, which might happen and could be even funny (in this case, no harm was done, since we weren't working in that area), I think that generally speaking, with the current market situation, which is already difficult cause the splitted market between FS9 and FSX, redoing a recently released scenery is a very bad idea, which doesn't make much sense. We try to be very careful with our choices, KORD, and then KJFK and KDFW were choosen because the last payware offerings were quite old, with a different sim, different technologies, different hardware and different user expectations.