It seems like a new feature as your vCenter is on 6.7 U3j 'VMware-vCenter-Server-Appliance-220.127.116.11000-16708996-patch-FP.iso'
This vCenter does not support upgrade to 7.0 GA, however supports upgrade to 7.0 U1 due to back in time release restrictions -->VMware Knowledge Base
I hope that helps
Seems like it's something that's enabled in latest release 6.7 U3j. It could be something enabled for upcoming upgrades, however I could not find much information about it.
I did come across another user reporting this issue -- > VCSA, upgrade from 6.7 to 7.0?
for me the only solution is to not install 7.0 this way. i am on the newest version and wait until the newest 6.7 patch shows up.
when i am able to upgrade to 7.0 i will use the install procedure vmware recommends