You can move virtual machines from one VM host to another. There is a compatibility matrix for ESXi versions and the associated version of the apps. Vcenter is a requirement to be supported in a specs based configuration. Even if you don't have support, it would be advisable to follow those guidelines for when you do renew support. Your best best is to use Vcenter to migrate them from one host to another. If you don't have Vcenter, you can use Vcenter in evaluation mode for long enough to do the migration. I would suggest adding this to the VM definition (vmx) file first.
uuid.action = "keep"
That should keep the applications from changing their UUID so the licensing MAC should be preserved. This is not for the faint of heart as you could really shoot yourself in the foot if you do it wrong. If you don't have someone with a level of comfort for these kind of VMware tasks, you are probably better off staying on your current host. You can also engage a partner to help you with that migration.
