I think you should be okay.
The DTZ2100D/G would still be considered a DTZ2100 model device.
For example, here is one an Amazon and you can see it just has a long hist of DTZ devices for the same adapter. https://www.amazon.com/Wacom-Cintiq-DTZ-2100D-DTZ-2100G-PSU/dp/B00N8PB3A0
Here is another one that lists the DTK and you'll see there are overlapping model numbers, and the plug end and voltage are the same.