For many years now, anonymous users who access a link to a question with no answers that's closed as a duplicate have been redirected to the duplicate target (so long as there's only one target). Currently, there's no indication that a user's being redirected.
However, this can leave a user confused as to why they were directed to a question that's different from the one they thought they were trying to access. The most common case I can think of is if someone's Google searching and finds a Stack Exchange question that's directly related to the thing they're looking for, only to be linked to a question that doesn't contain any of the content that the Google preview showed it as containing. I've been confused by this several times when using private browsing as well as in my main session when going to a site on which I don't have a profile. A similar thing also happens when an unregistered user is composing a question and follows a link to a potential duplicate which is itself an unanswered duplicate.
Also, if an unanswered duplicate's target is deleted (while this is restricted for users and mods, it is not restricted for the Roomba, plus there are older cases where it wasn't restricted), users will be redirected to a 404 page when following a link to a clearly non-deleted question, which can cause confusion.
When an anonymous user follows a link to an unanswered duplicate question and gets redirected to the target, can a toast notification indicating the redirect please be shown? Example:
You have been redirected from [Title of previous question](question link with
?noredirect=1to stop redirect), a duplicate of this question with no answers.