Entra ID integrated with Symantec VIP will automatically direct end users to the MyVIP Portal (self-service) if they do not have any registered credential.
This could be potential security concern if a bad actor was able to authenticate through first factor credentials and then be allowed to also register their own 2FA credential.
Symantec VIP integrated with Entra ID.
There is not a way to prevent the inline provisioning through Entra ID. The users will be created within VIP Manager and be automatically redirected to the MyVIP page after succeeding with first factor credentials.
There are policies however to limit the user's access once they land on the MyVIP portal page:
You can access both of these policies through the VIP Manager > Policies page. For a more detailed explanation of each policy, click on the "Edit" button and then select the "?" next to each policy: