Issue description: There is no way to block auto-assign roles for users in the Default Environment.

Example:

Users with the Power App license is always auto-assigned the System Maker role in the Default environment. Please note that we cannot remove it.

Actions taken:

I attempted to deactivate automatic license-based user role management and remove licenses for an organization. For further information, please refer to the following resource: https://learn.microsoft.com/en-us/power-platform/admin/opt-out-automatic-license. However, this process doesn’t apply to the default environment with specific roles.

From the document: "Does this impact the "Default" environment too? For the "Default" environment, Environment Maker and Basic User roles will continue to be automatically assigned to users even after opt-out."

Expectations:

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We should have an OOB workaround to prevent users, especially Guest Users, from accessing the Default Environment. Alternatively, if possible, the Opt-out option could be applied for the Default environment.