The dream was almost certainly a vision about the famous doppelganger guy getting hit. Otherwise there is no literary reason to have the characters mention him.
Actually, erm, since he looks like the actor, any chance he might be a replacement for that actor in a truck scene for some comedy? ( I don't know what they call it in movie industry). And of course she would be there too. Not sure, just my theory.
Chiyo chose the baseball team ending for Kishida instead of the isekai ending.
It does sound like the guy she saw was the actor who looked like him instead. That would still be kinda messed up, so hopefully that dude comes out okay, or at least, Chiyo sees which isekai world he goes too.