Hi foggy, thank you! This is good news as it helps in a large data center migration. I opened a support case yesterday and received the following response "The MAC address should remain the same unless hypervisor detects a MAC Conflict in which case, the vNIC is reconfigured with a new MAC Address."
I am replicating VMs across different clusters and don't know how a mac conflict would be detected.
With that said, I replicated all VMs from "cluster 1 (source)" to "cluster 3 (target)" and macs were preserved.
I then replicated all VMs from "cluster 2 (source)" to "cluster 4 (target)". During this replication some of the macs were preserved while others were NOT.