Not many details on this yet but there shouldn't be any major drawbacks since third party kexts can still be used to support legacy / multi-platform VMs or supp

Not many details on this yet but there shouldn't be any major drawbacks since third party kexts can still be used to support legacy / multi-platform VMs or supplement Hypervisor.kext in other ways. I doubt Apple would have bothered doing this unless they had a mountain of OSX crash logs / power consumption data that suggested they could do better. It's clearly in their best interest to sell stable computers that get great battery life so I expect they will do a good job here. Users don't switch between VM platforms often enough to know which one offers the best stability / power efficiency so there's less of an incentive for companies like VMWare or Parallels to make them a top priority.