Free Teams not truley free
So any company (Small Business 300 employees or less) that has Azure AD or AD sync maybe for onsite Exchange Server can't use free Teams. Even though they don't need any 365 Apps!!
I believe the Microsoft should re-think licensing for Teams. You are loosing a lot of opportunity. Once in Teams you might have leveraged some integration benefits to move customers to the 365 suite.
Yes it is not free