Ah.... a 17,OOO foot plunge in under two minutes, with some telemetry showing a peak descent rate near 30,000 feet per minute IS turbulence.
BTW, do you know how are these guys 🔽 are defying the G forces of a plunge like this 🔼 as they storm the cockpit? This is a big question out there. -- Thanks.

First, oxygen masks only deploy when there is a loss of cabin pressure, so they worked as they were supposed to and remained in place (undeployed).
Second, it is not the speed of the plane dropping which determines whether the passengers will be weightless, but the acceleration of the aircraft. A plane can dive fast enough to tear the wings off without the passengers ever becoming weightless, and the passengers are moving at the same rate as the plane, at least until the plane breaks up and they are individually subject to aerodynamic forces that will slow them to under 200 MPH.
In short, yes, despite the loss of altitude, they would be able to move about the cabin. NO, while the other flight with dinner dishes and mess, which hit turbulence, was a mess, that is attributable to more loose material in the cabin and turbulence, not an aborted controlled dive headed for terrain.
Google the "Vomit Comet", chances are they will better explain why no one was weightless better than I have.