My first impression of your first post was “foiled attempted suicide”. Or that one of the pilots was a sleeper agent for [somebody] who’d been activated to perform his mission. Be that a hijacking and hostage-taking, or a 9/11 style airliner-as-missile attack on [whatever].
The follow-on details seem to confirm some variation of that.
Losing 17,400 feet in 2 minutes is a lot faster than even a maximum performance emergency descent in that aircraft type: 737-MAX 8. Even if we make allowances for the worst case granularity of the data, that’s still a lot. Which also suggests they significantly exceeded the airplane’s operating envelope. Good thing it didn’t start shedding parts. Or if it did, they were not major ones.
And yeah, depending on how much more info comes out soon, this might be a good candidate for its own thread.