100% no one at the FAA would have spotted the original MCAS problem and they certainly didn't see the potential for an immediate crash following Lion Air; neither did anyone else, per what I have seen posted. Dekker had the chance in Jan 2019 - somehow still didn't see the problem until long after the second crash.
The original problem remained - the SMYD concept was defective going back to the start of the NG and the FAA did nothing about it. The "runaway" concept was a lie as well - clearly that predates the NG and still it isn't a top concern for pilot training. Both fall under the FAA and predate self-certification.