Re: right to repair (?)
Just to follow up: I've looked into this a bit more, and what's really going on is that by putting the memory "on" the processor chip, Apple is saving assembly costs for a penalty of having more CPU SKUs. But as "they" make the M1, that's less of a burden that it would be for someone buying an Intel or Samsung CPU: Apple can decide how many M1's they'll make with each memory capacity, and go from there.
So this is a production benefit (because they've eliminated the SO-DIMM PCB, the sockets, etc) not an architectural benefit. I'm sure the fact that it precludes memory upgrades is just gravy...