And if they're doing the new-plane certification and training anyway, the MCAS no longer has any point and could perhaps just be turned off?
Edit: Perhaps not— this comment asserts that the handling of the airframe sans MCAS is non-compliant with FAA requirements: https://news.ycombinator.com/item?id=21864584
* https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_orders_...
I doubt that doing a new type cert is tantamount to engineering an entirely new airframe. I think the thing that makes it less appealing to airlines now is the lack of faith in the integrity of Boeing engineering in general.
Airlines are in a tough spot as the only competitors to the 737 are made by Airbus. Airbus is, of course, up to its ears in orders and slowly scaling up the ex-Bombardier lines.
They might actually be better off just axing the MAX entirely and continuing to produce the 737 NG.
NG production ended (not without its own issues), it's not coming back. There is nearly zero chance of the supply chain attempting to retool for the NG. If Boeing can get the 737 MAX certified it will sell.