72 hour visa free transit only for direct transfer flights???

I have a open-jaw return flight ticket with Etihad as follows:
Milan -> Abu Dhabi -> Shanghai Pudong,
Seoul Incheon -> Abu Dhabi -> Vienna

After landing in Shang hai we will stay approx. 56 hours and then we're flying with China Eastern to Hong Kong. It is not a direct transfer flight, we will make our own way to Korea via Hong Kong.

Is it possible to use 72 hour visa free transit under circumstances mentioned above? Thanks