The Android Q preview released on March 14th 2019 comes with changes to storage access, requiring that any access to storage is done through the Storage Access Framework. From what I've gathered so far, file descriptors and fdopen still work in native code, but I have not seen any official word on whether or not native libraries will be able do fopen. My current understanding is that fopen will not work, even if the file is within a tree that the user has granted the permission to use.
I would love to hear what VLC Android developers think of this change, as well as the view of other users of libVLC for Android!
Links:
Android Q release blog
Scoped storage changes