I have 5 issues with the New Teams client:

1. What Todd posted below about the Policy Configurations.

2. Screen sharing button is gone - I am using horizon VDI with public preview turned on

3. In the Settings ] General ] System, there are 4 checkboxes. We cannot toggle the first (Auto-start Teams) and 4th (Register the new Teams as the chat app for Microsoft 365) - it will not allow you to turn it on.

4. The status does not automatically switch to away. it always shows you available.

5. Joining a Teams meeting starts the Classic teams client instead of opening in the new Teams.

My understanding is that Horizon Agent 2103 is supported per the Microsoft article.