Hello,
so to summarize, to me it seems like you are looking for a better backout-plan in case the migration does not work as expected. Your current plan is to delete the VS, and revert the Gateway/Management if something fails. That would not be my preferred way to do it.
You could test in Lab what happens if you just do a cpstop on the relevant VS, but I am not sure if you can delete a stopped VS or wether you had to start it again to delete it.
My preferred way would be to isolate the VS network-wise and, if everything works as expected, delete it after a week or so.
Isolation can work by removing all VLANs for this VS from the switchports your gateways are connected to. A warp interface to a VSwitch would be more difficult, there you could change the IP address or move it to another empty/dummy VSwitch.
Also keep in mind that by default, the highest and lowest VLAN on each BOND is monitored, so if your VS holds one of these, be prepared to see interfaces in problem state.