The public flight data looks very similar; for lack of any further details people will assume the problem had a similar root cause. Either way, his point isn't wrong- enabling a feature that can take control of the aircraft where it could not previously needs to be properly communicated. If pilots flew the older generations for several years they would not expect this behavior.

Not yet confirmed, but all evidence points to it.

Even without a single confirmed crash it's a strong SW security problem.