The trouble with these CM's is by the time you get your hands on CM5 and engineer your custom carrier board for it (because they change the pinout every time), Pi 6 has come out.
Hopefully they're sticking with the same connectors and pinout as the CM4. The Raspberry Pi foundation considers the Compute Module line to be non-hobbiest-oriented anyway. They expect people to be building around the solution offered as a long-term product. The NEC display is a good example, because NEC is interested in driving the display for the life of the display, not in customers replacing the CM4 when its EOL.