I also want to mention that each cell in grid view corresponds to a location in Legacy Container view now. They no longer default to the top-left corner in Legacy Container view.
Dropping an item in the top-left most cell (row 1, column 1) will put that item in the top-left most corner in Legacy Container view.
The bottom-right most cell (row 25, column 5) will put that item in the bottom-right most corner in Legacy Container view.