I'm not familiar with the plane and I'm not a pilot, but from reading the report it sounds like they were able to do the checks OK – but that took time.
It also sounds like the instrumentation displays on the plane very helpfully have modes and some kind of menu system. The references to stages of flight make it sound like these modes become available dynamically. So it seems quite probable that it isn't possible to actually navigate the screens in the air in the same way as on the ground.
Compare the 737 MAX8 cockpit [0] with the 737-800 cockpit [1] and the 737-300 cockpit [2]. Then consider that all of these planes are under the same type rating [3] – so a pilot trained on one of them is good for all of them.
There's also a lot of commercial pressure on pilots to not refuse to take off in a plane – which could lead to bizarre consequences like the airline questioning their competence for their current type rating.
[0] https://i.ytimg.com/vi/tCXPJkC7ZwI/maxresdefault.jpg
[1] https://drscdn.500px.org/photo/35641948/m%3D2048_k%3D1_a%3D1...
[2] https://magazin.lufthansa.com/content/uploads/2016/07/Boeing...
Are these changes not noticeable until you're in the air or should pilots have been refusing to take off in a plane they're not familiar with?