I think it would be good for the characters, in some way, to at least acknowledge the coincidence, even if they can't explain it. Answers could lie in how Ian ended up in that town. Maybe comparable factors were at work in both cases. Maybe something about that diner served to draw both of them toward it. Or maybe Rod Serling is going to step out of a doorway at any moment. Nobody seemed to question how Ilsa could have ended up in Rick's café (except Rick himself). But it was kind of a Mecca for lost souls and people passing through.
R