My mind is blown here. A regular use just created a Team from within MS Teams client application. This then created an O365 Group with inbox. It also created a new SharePoint site collection and locked out the administrators.
This is a governance nightmare and circumvents our security model, our information architecture, our navigation and branding. What is Microsoft thinking?!
O365 groups and SharePoint site collections should only be created by Admins (EVER). How do you disable the creation of 'Teams' and resulting site collections from the MS Teams client?