Was removing this a Mac thing only? There’s another thread about File > 3D Warehouse > Get Models… missing but I can see it in SU16, 17 and 18 on Windows.
Also the file menu is my preferred way to open the warehouse. In my view everything file related such as import, export, saving and opening belongs to file. I view the toolbar more like a billboard that advertises features for new users but would any day recommend new users to remove as much clutter from it as they can to avoid distractions. The Window menu also makes sense as it’s where the EW, Extension manager, Model Info, Preferences and other windows lives.