Hi Chris, yes for Android Wear and Apple Watch
I would not say that it is completely impossible, because everything is doable with enough time and effort.
But it is a quite unusual requirement for Mendix and would not recommend doing it.
EDIT:
If you only want to extend a separate SmartWear-App to integrate into a Mendix (via REST etc.) I would say this is quite easily possible.
But generating a SmartWear-App out of a Mendix Project is afaik not supported with vanilla Mendix.