Eh, stuff like older vxworks plays loose and fast with the term microkernel that wouldn't fly today. I don't even think they try to claim that it is one anymore until their most recent release where they actually added (optional) process isolation.
Microkernel as cpu architecture abstraction layer. Such are only accidentally microkernels and not OSes at all as i understand them. They deliver on what of all those wonderful lists of microkernel benefits?