No, "chin" is not intended to include head or temple shots. It's certainly part of punch resistance, but it's *different* from getting knocked out with a shot to the jaw.
I know that anatomically it’s not the same. But it’s used to refer to punch resistance to the face. If a guy can’t take a punch he’s called glass jawed/chin regardless of where in the face he gets hit.
The terms "chin" or "jaw" properly understood in this context, translates into punch resistance, generally. A fighter who hits the canvas due to punches above the chest may be someone who has chin issues.