Ian W,
Google's chess playing system AlphaZero simply used "machine learning". It was told the rules of chess and then played against itself a gazillion times, randomly initially, with a simple reinforcement algorithm by which it eventually "learned" good moves vs bad.
That's just statistical analysis of big data. Something computers are good at. Artificial Intelligence it ain't. And it certainly takes us no further towards the holy grail of Artificial General Intelligence.
To translate that to autonomous aircraft would involve crashing a gazillion aircraft in real world conditions until it "learns" how to not crash. Sorry, but playing chess isn't transferable to a dynamic safety system in the real world.
In the global race towards autonomous cars, not even the companies themselves are in anyway pretending their vehicles will be "intelligent". They won't be. They will be following simple algorithms based on big data. When they get into trouble, they will just stop, much to the annoyance of human drivers (I'm sure we'll hear a lot about that in the coming decades).
Aircraft can't stop.
And to put any timeframe into perspective, I still have to read 50 pages of NOTAMs everyday that are still formatted for teletypewriters.