I’m confused... other comments reference ME as the root-of-trust for the system, the chip that brings the CPU out of reset. How can a system be operational without that functionality?
You can "disable" the ME but you can't disable it. People are being loose with terminology.
Why wouldn't it work? Intel-based motherboards didn't always have a ME.
Current Intel chipsets and CPUs cannot initialize the system without the ME. You can disable all the applications running on the ME, but it is required to bring up the system.