Looks like any Power BI App shared with the Entire Org is visiable to the External Users once signed up to view the first App. By clikcing on App then Get More Apps they can see all Apps Shared Inte...
AdamWilson
Microsoft Employee
Microsoft EmployeeThanks everyone for the feedback. We have changed this behavior and now apps shared with all users can only be installed by internal users, not external B2B users.
You can always use usage metrics to see which users are accessing content in your app and you can unpublish and republish your app if you want to remove access from users that have already installed it.
To share an app with external B2B users, add them explicitly to the app (either individually or with a security group) and they will be able to install it.