Fairly sure most iGPUs these days are zero-copy and can dynamically allocate memory so what does "unified memory" mean to you exactly? A wider bus would be nice but it's not exactly a groundbreaking new invention.

Or just buy a MI300A server like https://www.servethehome.com/gigabyte-g383-r80-aap1-amd-inst...

Raspberry Pi and other SBCs, Android phones and practically all of the embedded devices with a display and microprocessor.

All have unified memory. Linux runs just fine on all of those.