It is a bit more complicated. This isnt just black paint. It dries into tiny 3d structures. These are very delicate little hairs, easily brushed off by any slight abrasion. Dirt is a problem, but airflow at speed (dust in that air) would be enough to remove this coating within hours.

Slight nitpick, but they are not using the original vantablack with a thread like structure in here. The article states it is a new compound with a sponge like structure.

But there's no reason you couldn't use it as an ultrablack pigment layer and simply tolerate the presence of some highlights. Wouldn't even have to be 'matte' surface, you could put a high gloss surface on there and still have it be different. Because it isn't just black paint, because it's a sponge-like structure inside a medium, that means you can use it as a simple pigment in a normal paint job, and it would be blacker than normal pigments in that context.

Might be possible to make an 'ultra gloss black' in that way. Highlights would reflect, but anywhere that isn't a highlight would be the depths of space. The glossier, the more extreme the effect.

Yes. Same problem as Ever-Dry, the extreme water repelling coating, which is also a surface of lots of tiny hair-like tubes. Great concept, but the effect that makes it work also makes it fragile. You can't coat either with something smooth and hard, or you lose the effect.