One SBC with multiple tenants: -ForwardPAI $trued

In the link:

Configure Session Border Controller - Multiple tenants - Microsoft Teams | Microsoft Learn

The following command was used to register the carrier trunk 

New-CSOnlinePSTNGateway -FQDN customers.adatum.biz -SIPSignalingport 5068 -ForwardPAI $true

Is there a specific use of -ForwardPAI $trued with the setup of "one SBC with multiple tenants"

or

It is just a recommended way of registering an SBC?????

-ForwardPAI $trued forwards P-Asserted-Identity (PAI) header