India -> (connect in Thailand) -> Shanghai -> Hong Kong

My wife and I are USA passport holders.

We will be leaving on an itinerary from India (BLR), connecting through Thailand (BKK), then landing at Shanghai (PVG). Within 72 hours, we will depart from Shanghai (PVG) to Hong Kong (HKG).

1) Can you confirm this qualifies for the 72-hour free transit visa?
2) Also, should we inform the airline in India or Thailand about our transit permit request?

Thanks!