Did you know: Admins will soon be able in mid-March 2020 to pre-install apps that will be visible when a user clicks the the ellipses (…) on the left rail of the Teams desktop app av and completed by early April
This message is associated with Microsoft 365 Roadmap ID 61332.
How does this affect me?
You already have the ability to pre-pin apps for your end users. We are adding a new setup policy that makes it possible to pre-install apps that your users will see immediately when they click the ellipses on the left rail of the Teams client.
Note: that when you install the app for your users, they cannot uninstall the app. You would need to remove it from the list of Installed Apps in the Setup policy.