At the start of ''Devotion'', you can see the ''Goodbye time traveler MC'' saying something like '' they are back'' which is because they sensed the return of the player but that's it. Destiny can't use the player again as an ''observer'', CC can sense the player but if she admits it or informs other characters about the ''real truth'', the ''SYSTEM'' will delete her just like it did back in ''Null''.
Zero also knows about the ''real truth'' but she finds it more interesting and fun to not tell anyone.
Zero is just being Zero.
Reeva knows about ''the village'' but she has no idea about ''the real truth''