SEQUAL CONTENT. WHY ARE THEY LIKE THAT. but also how do they communicate :0? is it a mind reading thing or a sign lanaguage/ body language thing or something else?
this is a little bit of a conundrum to answer because, with some additions here and there, i love to have 527 mirror Stanley constantly. this is just his thing, primarily being a foil. the problem here is that "Stanley" isn't a rigid personality and even the way he communicates with the Narrator in fan interpretations varies. so while 527 is more solid of a character than Stanley is, there are these little things that are more fluid (and i kind of love it)
however, what makes things easier is that definitively the American Narrator's telepathic communication is one-way. call it radio. though, depending on what part of sequel content it is, he'd be talking anyway
i do also think 527 might've snagged (or been granted) a whiteboard marker - those scribbles on the meeting room walls during Figley must come from someone, right?
regardless, with 527, it'll probably be mostly body language with a side of writing. i personally also like to think 527 knows sign language but its like a case of the ol' Chell Portal "doesn't really have anything to say to you"
as for what's wrong with them...
i think they're just like that