SCMP showing pax stranded everywhere. A'EX back up but MTR was halted in some places and the roadway to/from HKIA was full of protesters walking.
Some flights inbound to HKIA have been diverted, others turned back (e.g. to SIN).
Photos here
https://www.scmp.com/news/hong-kong/...d-mass-protest
Even if HKIA cancelled flights and AC 8 was among them, there could also be the issue of some of the 450 pax not being able to get to the airport.