Impact/Risks:
Changing the storage policy for workload VMs requires a vSAN resync to occur. There is a possibility for increased vSAN latency while the resync happens. Additionally, the more data data needing to be resynced at once, the longer the vSAN resync will take. Because of this, it is smart to work in smaller batches of VMs to allow for the vSAN resync to complete between each Storage Policy update.