The Hurd is actually older than Linux now at a ripe age of 32, although I think it was Mendel Rosenblaum that said "hypervisors/machine monitors were microkernels done right".
Modern hypervisors are more or less modeled on microkernels, not the other way around. Microkernels are just naturally a good fit for hypervisors, hence why nearly all commercial microkernels have an embedded hypervisor solution.