There's a well written CNN article that describes the issues surrounding this event and the lack of information around MCAS.
In particular one learns that Lion Air has ordered $21 Billion of Max 8 737 Boeing jetliners in 2011, and another 6 Billion worth of Max 9 and Max 10 this year. That's real money. One could assume that Lion Air would expect to be a priority recipient of training information concerning these airframes.
Speaking as someone who has 20 years experience as a journalist, I'd say that a lot of people in high places in the industry and regulatory agencies must be very upset about this event for CNN not to whitewash Boeing as they usually would, and take the trouble to generate this very carefully researched and written piece.
Edmund