I think you must be confused... Flightbeam has currently developed only KSFO, KPHX and KIAD and are currently making KDEN and an unannounced airport (that I doubt is KIAH because they and FSDT are more of a team than competitors I believe). So FSDT are the only ones working on Houston's "megaport."
After Houston, I'd like to see (besides the expected updates of KLAS and perhaps KORD) KSEA or a smaller time airport like KCLE or maybe even KATL (even though imaginesim updated theirs), and I know Umberto said they were thinking about KATL as well. I'd love to see KEWR but I think the NYC area is already so fps heavy and with KJFK, etc it might not be the most practical. Plus Drzewiecki is still working on their NYC airport project.
It would also be really cool if they considered doing a big non us airport like VHHH or RJAA. Still, I bet whatever they do they will do one hell of a job with it as they always do.