A bit simplistic, but...
...if you get AI to study outcomes and the ways they were achieved by human ATC bods, then all you've ended up with is a system that will 'think' like a good controller given the constraints of performance and sep'n standards, and in the future, come up with solutions that the ATCO at the time will probably have already (or shortly thereafter) come up with anyway. All you've added is a distraction.
Any further improvement needs to see a change of separation standards, and/or the building of lots more runways.
OT: Last century, the Oz ATC PHBs in 'Bullsh1t Castle' decided that there were parallels between trains and aircraft. They got in a train expert and asked him how to improve efficiency in moving aircraft. After an appropriate period, his (because they were always 'hims' in those days) report said that aviation had it all wrong. Railways had (generally) two lines between main stations, and lots of platforms at each end. Aviation had lots of airways and only one or two runways at each end, and hence had it all backwards.