https://www.lenovo.com/us/en/p/laptops/thinkpad/thinkpadp/th...

That particular source is sold out but it's not where a computer manufacturer is getting parts.

The availability is real. You can buy a thinkpad with LPCAMM2 right now, and in fact you've been able to buy that laptop for over a year. And you can get it with 64GB modules, which is what you'd need to set up 128GB on a 256 bit memory bus.