Ask them specifically instead of random or vague guesses that they’ll attend. The admit webpage specifically says that only the students belonging to high schools that are in the areas listed there will be able to register for events, not others. It’s possible that the students you are talking about may physically contact Stanford or AOs due to being nearby and thus maybe able to get entry into events but as far as the webpage is concerned, only the students from high schools that are in the areas listed there can attend. If you still have doubts, you can look at this astrology and how it worked from the last year.
Here is the link:-
Stanford Class of 2029 Official Thread
Scroll down to 269th comment and you would see the discussion going on from there where the astrology is mentioned and when the decisions were released, how it worked.