The new VCenter may not show up in any of your data. Except if it is a VMGuest, then you will see the original VMGuest stop showing new performance data and the new VMGuest with performance data.
Vcenter name doesn't really get loaded into the performance data... only the ESX Host and VMGuests.
When the new ESX hosts are built, if the name is the same then you will see a "Configuration Change" showing the ESX host upgraded to new hardware.
If the name changes then the old one will remain, but no new Performance data will be collected for it.
The VMs migrated to new ESX hosts will show up as a MOVE from the old Physical_Host to the new Physical_host.
DataManager will handle it without any problem.
David