Incoming calls routing on surrogate agent

Hi,
The operator I'm connecting to requires me to register with a predefined phone number as my identity (Register Contact User).
Assuming that I'm using the following number range 123456700 - 123456799 and assuming that I'm using 123456700 as the register contact user in the surrogate agent.

I noted that incoming calls to the register contact user number are routed to the Customer Next Hop defined in the Surrogate Agent configuration - no local-policy is required or applied.
As the same time incoming calls to all other numbers in the range require a corresponding local-policy to be routed.

1) Are my observations correct and this is the expected SBC behavior ?