Apple uses end-to-end encryption for iMessage, which is the only Apple-related confidential communication I can think of (well I have no idea what the guarantees around FaceTime are).
Beyond explicitly using secure notes (which are encrypted), I don't recall Apple promising "confidentiality" of those things. I mean, I don't expect Apple to give that data to others, but I also don't assume Apple has no way of accessing that given a court order.