Wel, yeah, it is in fact a mixed realty headset, clearly. But Apple’s emphasis on mixed reality is more towards the spacial computing aspect within it which is why they prefer others think of it as such. It doesn’t matter what you or I think, it’s Apple’s device, and they’re focusing on the general computing capabilities of it.
So we’re all free to call it whatever we want, Apple just wants developers stick to the game plan, and you can’t really blame them for wanting that. They don’t want it pigeon-holed into just a “VR” device, which is exactly what we’re seeing on this board in some of these posts, because there’s a connotation with “VR” that immediately brings up thoughts of a gaming toy…. which is basically all the mainstream thinks of these headsets so far.