The GTD and GTI do not have thesame suspension. Based on VW UK, the GTD is .6" lower than standard Golf suspension, while the GTI is .9" lower than standard Golf suspension.
The North American Golf 2.5 is getting a standard suspension, while the GTI is listed as getting a "sport suspension with lowering". The TDI on the otherhand just says "sport suspension"???? which I will guess is half way between the 2.5 and GTI.
So...we might be getting the GTD suspension in the TDI, but wont know for sure untill a properly finished the full spec-list surfaces.