I keep seeing conflicting information. Reference Previews work fine on my wiki for logged out users, but when logged in they stop working. Page Previews are enabled by default and also enabled in the user's preferences. I've seen a thread or two on this forum as well as this post in the project hub (T278739).
It's not clear to me if they should work, if they conflict with something else, or just don't work for logged in users (not sure why?). My wiki is just local testing and is basically a stock configuration with a mobile skin.