This feature request is working its way through the backlog queue. No new details are available yet.
-WarrenLaura supported this idea ·Laura commented
We are using SharePoint Team Sites and when taking Teams into use, we want to be able to link Team with an existing Team Site and that Team Site's document libraries, NOT create a new group Team Site -> We end up saving documents into two different Team Site document libraries (the existing, "old" one and the "new" one created together with the Team). This is a BIG hurdle, hope you will get this solved soon!