I was also thinking that with the pi400, but that was clocked a bit faster than a pi4 if memory serves (the heatsink). Still, it would have been nice to have a CM5 that could later be upgraded to CM6.
Anyway it looks like a wait and see for the Amiga500+ version for me, that M.2 prep. looks worth waiting for. Any maybe they got some more red paint in by then.