VW aren't very good at showing the correct model-specific options within the configurator, some of the options shown are generic to all models and some aren't even relevant to certain models.
I've just checked the configurator for my Polo GTI. It also shows an optional tailgate spoiler when the car already has one (to be fair, it does look a different design to the standard one). It also shows as options door sill trims (not required as already fitted), mud flaps (can't be fitted, due to GTI-specific bumper/sill profile) and the flexible load liner for the lower boot floor position (no lower position in the Polo GTI, due to battery location).
Whether it's possible to fit the mk7.5 Golf optional front / rear spoilers shown in the configurator to the GTD is anyone's guess; they look different to the standard offerings but would you really want to spend £760 on these, and then pay extra for fitting and painting?