If demand is exceeding expectation then its funny how i can go to 3 or 4 sites right now and order one or two with no issues.
Demand might be there for the aio one and the aluminium shroud version, but its not there for the basic black shroud version.
AMD saying that was very obviously marketing, I don't think they can afford to sell them at a competitive and reasonable price long term so they have to create the illusion it's selling well at the current price to justify not lowering it.
If it's a yield problem then it's possible that Vega 56 will be a lot cheaper but I think the HBM process is what is making them too expensive. If it's both then it's understandable AMD don't want to sell many.