Boeing is said to have a contract with Southwest about the MAX. Claiming it would need to pay 1 million dollars per aircraft ordered if MAX pilots need more than CBT. Stuff like this. Not much might be known outside. EICAS would change procedures. The fact that they did not install it yet seems to indicate how tricky it is.
And the more Boeing changes the closer they come to the legal tipping point where authorities don't accept grandfathering anymore whenever "more than 50 percent" is considered to be new.