I think the definition on wikipedia is in the ballpark, but not completely accurate. AMT is a set of functions that can be enabled by configuring specific vPro technologies (key being cpu, chipset & wired & wireless lan adapters), not just the cpu. Initially, it was just the lan adapter.
By neutering the IME, such as with the methods discussed by Positive Technologies, you break the configuration that enables AMT functions, such as remote management.