Failover IP blocks in vRack - do we need to remove existing vMAC assignments?

Hi
We are planning a large restructuring our server infrastructure on OVH dedicated servers.
Currently we have various blocks assigned to individual servers and therefore these are also assigned vMAC addresses, which are in return set as the MAC-address of the virtual servers that we are running.

Does anyone know if we need to first unassign all the vMAC entries from the individual IP-addresses in the netblocks before moving them to the vRack or can we simply move it and vMAC will automatically get unassigned?