Confused on the "Key Point" above

Above, it states "flying in and out of China – from A to B and from B to C – should be non-stop, without a stopover anywhere in Mainland China." Does the flight really need to be non-stop or is ok to have a stopover as long as it's not on the mainland. I'd like to do US to Shanghai to Hong Kong then back to the US, but on the flight to Shanghai there's a lay over in Hong Kong. Would I be able to do this visa free even though I have a stopover in Hong Kong on the was to Shanghai?