Turn off Teams Preview by Default

VNJoe  Did you figure this out?  I just discovered that all of our users are using the Teams Public Preview version, even though the default Global policy is not set this way.  The Global update policy says that users should only get the Public Preview of Teams if their MS Office is set to Current Channel Preview, and our users are all on the Quarterly Enterprise channel for Office.   I created a new Teams Update Policy and am applying it to users manually.  So far the Policy does not force their client to downgrade their version to the GA release, but it does remove the "Preview" notice and I can see specific Preview features get turned off.  

We've been dealing with a bunch of weird bugs in the client lately and I am really frustrated that they were getting the Preview version despite our policy being set to avoid this.