I have never used vSOM but i am guessing this is just a bundled version of vrops.
If this is the case the main thing is all objects will be classed as new when you move them to the new vcenter and you will have duplicates until the history and deleted items time set in the golbal settings expire the object
depending on how your custom groups are created will determine if your policies will get applied
We just when through this but we have all our groups set as relationship, descendent of the CDC. All we had to do was remove the old vcenter cluster object from the CDC and add the new vcenter cluster object and the clusters, hosts, VMs and datastores got there correct policy without any further configuration
It's still vROPS, vsom just gives bundled licenses.
I went from 5.5 windows vc to VCSA deployment. I left same IP's and name so I didn't have to re-target, just kind of reconfigure due to certificate mismatch.
Anyhow, yes, no issues and 100% continuity on data for vcenter collector.
To answer your question, if you build a *new* vCenter and just swing the hosts, this will throw vROps (regardless of how that came purchased and packaged in vSOM or stand-alone, or vRealize Suite, or etc.) into disarray. This is due to those VMs getting all new reference IDs owing to them being managed by a new, different vCenter. If you don't want this to occur, you should upgrade your vCenter instead (yes, an upgrade/migrate to the vCSA counts as an upgrade here).