You could be right but we will never know unless someone from Apple really confirms the reason behind the trouble of the release of the Space Black watch.
I really am hopeful being the first batch of people to receive this particular watch that this only affects us or maybe they'll fix it with the next batch.
I just got back from the second Apple Store here in HK and this one too didn't have any Space Black units for demo. How weird is that. They sent them back to be recoated perhaps?
Very few Apple stores in the USA have this model available for try on. So I'm not surprised that they are also in short supply in HK.
Is the problem with your band limited to a single link? It looks like it from the pictures, but I can't tell for sure.
That link may have somehow missed a cleaning step or some other surface preparation prior to DLC coating. It could be as simple as someone touching the part with bare fingers after it was cleaned. That could keep the DLC from bonding to the metal as it should.
I expect Apple will give you a replacement band eventually. If they had plenty of them available, they'd probably just swap it immediately. But they don't have them.
It's very unlikely they'd try to recoat a defective band. They'd have to disassemble all the links, strip them down to bare stainless steel, and then repeat the whole DLC application process from start to finish. DLC isn't like paint, where a second coat can hide minor imperfections in the first coat.