In the end Muilenberg will be fired. First the CEO is the fall guy if the s**t really hits the fan and they get paid accordingly. But the whole saga after the grounding just looks bad, from "making a safe plane even safer" to missing one self defined deadline after the other. In addition all problems in the cooperate structure discovered will be linked to him, because making that work is his job.
Yes, I think the "making a safe plane even safer" statement was tone-deaf and showed he and his team did a terrible job reading the situation. They seemed to think the public would think logically and say if NG is known to be safe then we improve MAX by getting rid of MCAS 1.0 and adding other fixes it will be even safer. They didn't seem to understand the public was thinking emotionally rather than logically, for what should have been obvious reasons. It made Boeing look like they were in some sort of bubble, out of touch with the real world.
To me what is even more damning is that he personally said shortly after the 2nd crash that a review of all internal processes was conducted and all were followed. Now we read the JTAR report and contrast what JATR is telling the entire world with DM's statement, one where no proof was offered. It makes it look like either no one in Boeing was capable of looking at the situation the same way JATR did, or they did so and saw how ineffective their internal processes were and chose to self-censor to avoid making the same kinds of conclusions JATR made. I think it was the later, which was a classic corporate equivocation. I realize he was trying to make the best of a bad situation, but I think a different course could and should have been found.
Personally, I don't see how he survives the aftermath of the MAX crisis. If I was a Director, I'd vote to give him the sack once MAX is flying again, and that's what I bet will happen.