Given the latest MAX issue in the non related MCAS system encountered by the FAA and the difference in classifications used by Boeing compared to that of the FAA.
It is reasonable to believe that further changes (fix's) will be required once more testing is carried out by FAA and other regulators.
At what stage would Boeing need to give up on the requirements of Computer Based Training, hardware changes and/or Grandfather rights?
They have delivered a reasonable number of these aircraft to customers that will be wanting compensation, they are still building the aircraft at a reasonable rate and clearly they need to invest and expedite a Clean Sheet replacement - one assumes under closer scrutiny (less short cuts) by the regulator and expanding interest in the 787.