I was wrong about how the PIN is utilized, but your comment is a red herring, as was Claudia's. If an EMV transaction does not require a PIN, then it's not the system currently being considered for use in the US. US FIs are considering the older chip-and-pin system.

As an academic matter, it's interesting that you mentioned the chip-and-sign approach of HK/Aus. But as a practical matter, it does not make sense to take the merits of the HKs chip-and-sign system, and try to claim that this somehow applies to the chip-and-pin emerging in the US. Both the exploits and the legal risks are substantially different between chip-and-pin, and chip-and-sign.
Good article. Should be required reading for the thread. It reinforces the importance of the signature.