This isn't just a supply issue. I think AMD expected solid demand. The demand has been absurd. Discussed this with the Microcenter guys from a mainstream end and they're seeing far more AMD units moving than even on Zen+ launch. Intel is sitting on shelves rotting. For HEDT they state that when the financial guys come in and state they just want the fastest chip for their heavy multithreaded, multi-program workload, they present Intel and AMD, and the users are taking AMD due to core count and cost. So in the end, I think it's not just supply / binning, it's also that demand is (good for AMD) outstripping even their expectations.
Of course, my above experience is anecdotal and I have no idea how the market is outside of this one Microcenter Dallas store.