Yes. As explained on the manual, terminal D doesn't even strictly have the SafeGate systems to begin with.
But, since KLAS is scheduled to add them anyway in 2010 (perhaps with the opening of the next planned terminal which will appear in the big under construction area), we thought it would have been nice to have them at least at Terminal D, which is the more recent one.
Normally, marshallers are far more common in the US (while SafeGates are more widely used in Europe) so, the next logical step of the ParkMe feature, would be adding support for them, which is something we are working on. Once we have them, we'll have ParkMe enabled at all parking places.