This is Intel not AMD. AMD only had 1M Zen 3 desktop chips when Zen 3 launched, which is why the scalpers took control for ~6 months. My guess is this will look like any other Intel launch, the first batch will last about a week then get scarce, and within 6 weeks there will be plenty of supply at MSRP.
On the performance side, I'm not real enthused about having to upgrade to Win 11 to get the benefit. It makes getting anything above a 12400 kind of dubious if you want to stay on Win 10 or don't want to spend $200 on the upgrade (Pro cost). A lot of DIY types will probably fail to note this and thus not factor it into the cost of the upgrade, but DIY is a tiny part of a small (desktop) market.
I really kind of rate this as both incremental in terms of performance (so Intel can beat 5900X now and jab at the 5950X), but an important step in getting things like big.LITTLE, PCIe 5.0, and DDR5 into the mainstream. Intel is moving fast now and Gelsinger is clearly willing to spend money to be #1 again. AMD will need to pull a rabbit out in 2022 with Zen 3+ and Zen 4 else face a repeat the FX days.