Having been involved in the early years of the 737 as a BSEE developing automated test systems for the aircraft I can say that the development\testing\review\approval of the software systems is more stringent then anything I have seen in my 30 year career.
I would say it is impossible for a single disgruntled person to affect any change after approval.
What of the Max 9's? My understanding was that they had the same Engine placement changes that required the Angle of Attack Sensor feed. Are the Max 9's still flying?
Begs the Question when will Trump nominate an FAA administrator? All three are acting...
Obviously not a priority for this administration.
https://www.faa.gov/about/key_officials/
http://fortune.com/2018/01/05/faa-chief-steps-down-donald-trump-tweet/