I think you can see them in the new Folder app but in order to transfer files you still need to:
- desktop/laptop and iTunes to copy them to your iDevices
OR
- put video/music et.c on Dropbox, Box, Google Drive and then access them via the Files app. Not sure if you can take it offline though in the Files app.
Please note that third party apps which you use to access video,music, etc. from e.g. Dropbox, Box, Google Drive but then you probably wouldn't see them in the Files app but only in the third party app where you imported (cache/offline) the video/music to e.g. Infuse, nPlayer (both video) or CloudBeats Pro (music).