Way back in 2013, I published Preserve your Veeam B&R Backups Jobs when Moving vCenter, outlining how to «cheat» (by using a CNAME alias) to preserve your Veeam Backup & Replication jobs if you replace your VMware vCenter.
Naturally, when there is a new vCenter instance, all the Virtual Machine Managed Object Reference’s (MoRef) change, which makes Veeam Backup & Replication start a new backup/replication chain, since all VMs are treated as new ones. Not ideal by any means, but at least you wouldn’t have to recreate all your jobs.
Veeam has now made a tool available that can map old MoRef’s to new MoRef’s in your backup jobs, in order to keep your incremental chains intact even after replacing your vCenter.
Check out vCenter Migration Utility!