AvHerald says the accident aircraft landed at 15:41Z; passengers were kept on board of the aircraft until arrival of the replacement aircraft because the airport does not have stairs to accomodate the A380; AF's 777 arrived to pick them up at 05:50Z and departed at 09:55Z (and a 737 for the rest of the pax somewhat later).
Incident: France A388 over Greenland on Sep 30th 2017, fan and engine inlet separated
If that's accurate, pax were on board the A380 at Goose for between 14 and 18 hours. No explanation of how they got off the A380 if the airport doesn't have stairs for it; I suppose the airport improvised something. Anyway, as others commented up-thread, (a) the airport probably couldn't accommodate over 500 pax and crew; (b) if they'd got off, rules (aka bureaucracy) might have required them to be processed by Canada immigration, which would have taken forever.
I haven't seen any complaints from pax, so I guess they were kept comfortable enough, and if they'd seen the engine, glad to be on the ground.
I suppose the airport was able to provide ground power and/or refuel the APU - or would there have been enough fuel on board to run the APU for that long? And ... I wonder if the airport was able to provide food and water .. and if they were able to clean the toilets during the wait ...