If you see the traffic in that region, I think it’s enough for several big Airports (SIN, KUL, BKK)
Hopeful TG (which have an excellent service, I just flown with them) then have the chance to grow like SQ does in the past and became an much more important carrier.
P.S. The old BKK Apt. is really an worst one, you arr. by an 744 an got an Bus transfer to the terminal which take up to 10 Min.