Understand that VMware should be fixing this instead of trying workarounds but you could try the guest CPUID masking.
With this Tech Preview, it identifies the macOS guest CPU as Haswell Ultrathin while it identifies the host 2017 MacBook Pro, (correctly this time) as Kabylake (versus Pentium 3 in Fusion 8.x) and presumably the incompatibility error is because of that.
2017-09-14T15:23:56.019-06:00| vmx| I125: guest vs. host CPUID guest codename: Haswell Ultrathin
2017-09-14T15:23:56.019-06:00| vmx| I125: guest vs. host CPUID *host codename: Kabylake-S/H QS
Try either tweaks to the vmx configuration file of the guest macOS VM to make the guest CPU to be identified as a Kabylake instead of Haswell Ultrathin.
featMask.cpuid.Intel = "Val:1"
featMask.cpuid.Family = "Val:6"
featMask.cpuid.Model = "Val:0x9e"
featMask.cpuid.Stepping = "Val:9"
cpuid.1.eax = "0000:0000:0000:1001:0000:0110:1110:1001"
I'm hoping VMware can get this fixed very soon. I'd rather not spend time playing around with unsupported workarounds when VMware is making this effort to provide us an exceptional product.
Spoke with VMware Support: this should be fixed in the next Preview build...