When NSX is upgraded from prior release to multi-tenancy supported NSX release (4.0.1.1/4.1.1) the existing configuration remains intact and there is no impact on the configuration or the functionality of the network objects.
Avi Load Balancer integration with NSX for deployments without multi-tenancy (NSX Project, NSX VPCs) will continue to function the same way without any change.
The following diagram shows the NSX object model with the multi-tenancy of NSX Projects.