Generating An Empty Global Address List By Default

Hi CSU_Scott,

In that case, I guess  the only solution for your scenarion are the Information barrier policies.

"If your organization is in https://learn.microsoft.com/en-us/microsoft-365/compliance/information-barriers-multi-segment?view=o365-worldwide#check-the-ib-mode-for-your-organization or multi-segment mode, information barriers is no longer based on Exchange Online Address Book Policies (ABPs). Organizations using ABPs will not have any impact to the existing ABPs when enabling information barriers. If there's no ABP defined for users with associated IB segments and policies, an ABP is automatically created with empty address lists for these users. You can change these ABPs as needed. We recommend that your ABPs are consistent with the segments you configure in information barriers. You should try to avoid user visibility differences between your existing ABPs and your new information barriers configuration."

https://learn.microsoft.com/en-us/microsoft-365/compliance/information-barriers?view=o365-worldwide