I think we're talking about two different things. BMCs run separately from the rest of the system and are active even when the machine is halted. They provide remote mouse/keyboard/monitor, power control, remote device mounting, bios settings, hardware sensors and monitoring, etc. These have been in servers for ages, do the same thing as IME, and are way less secure. None of it has any relevance to software updaters or software at all really since a lot of these boxes are shipped without an OS or even hard drives.