One would like to hope, particularly being aviation, that there would be a straightforward plan for everything that was done, and needed to be done, and progress seen as it was worked through. Yet with apparently just 20 days to go there has been no sign of this at all, just speculation and opposing views, no credible statements from those involved, etc. It just looks like Boeing are sleepwalking into it. Possibly their board have been hoping that the Ukraine situation will lead to substantial military aircraft losses and the need to re-equip same at full list price.
And regarding incompatible aircraft, carriers have long had a range of incompatible aircraft in their fleets. Sure, at the margins of cost it can make a (bit of a) difference, but nothing like the hoopla that seems to have gripped some commentators. Plus I suspect the 737 would be very difficult to re-engineer at this stage for such an operational difference; I wonder how much design effort, if any, Boeing has put into evaluating how to do it. Better spend the money on stock buy-backs would be their board's view. Regarding the Southwest pilots voting "without" for the new versions, I suspect they have only thought about their own standing, promotions and seniority in a divided fleet rather than anything to do with developing safety standards.