Well, at least Pine64 makes one. I have no idea if those are pin-compatible with Pi compute module, though.

https://www.pine64.org/clusterboard/

It's a bit sad the Pi foundation dropped the DDR form factor, though, it was a good idea IMO.

For this, they could have gone with an EOMA68 form-factor, that would have been awesome: https://www.crowdsupply.com/eoma68/micro-desktop