IDs like MAC, UUID, WWPN, WWN get burned once the service profile is associated and they do not change during reboots. If you remove blade2 during initial reboot it will still gets its own ID because it is burnt in because of the service profile. Only if you disassociate the service profile and use that IDs to another blade it will use the free IDs available from the pool, at that point it might get the same ID which blade2 had