As in the past you can right click on an example of a filetype > properties > open with & set vlc to be the default for that filetype.
What has changed is now the default video & or default audio player setting will set chosen player for all mimetypes that are supported (in the past it only set for 1 mimetype
To try out > System Settings > Details > Default Applications > Video > pick Vlc media player.
After doing so, to see changes, open this file
Code:
gedit ~/.local/share/applications/mimeapps.list
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