ESXi version for BigIP 16?

I would open a support case to get confirmation, but that appears to be the case.

There is a reason why 16.1.x is not supported on ESXI 6.5 . 16.1.x has the configuration related to new VM hardware version , On the latest releases of 16.1.x ( we have the VM HW version 13 ) which is not basically supported on ESXI 6.5 . The VM boot up will get failed if this version is installed on 6.5 and thats the reason Customers are requested to deploy the BIGIP VE on 6.7 and above which supports hardware version 13