It seems to be more that they are simultaneously launching and killing the product.

Sounds like they entered into a contact to develop and sell the CM0 to several large manufacturers who happen to all be in China, hence the launch. But then discovered the supply of ram chips that it uses is extremely low (they apparently stopped manufacturing them years ago) and they want to direct as many of them as possible towards the Pi Zero 2.

So we will probably see a follow up to both later, and the CM0-B (or whatever they call it) will be more widely available.

Possibly for the same reasons there is no equivalent to JLCPCB outside China.