At the moment, our application design allows any managed user to be invited to an Atlassian cloud side or product residing outside of the managed user organization.

The invitation results in an email sent to the users who can then join the site with the link sent by email.

It would be nice to allow org admins to block managed users from being invited to external sites, as some organizations have security requirements to not allow their users to join other sites and products apart from the ones they have.

At the moment there is no workaround for that. The customers can work with their email team to block or filter emails that contain the invitation sent, but users are still invited to the site even without receiving the email