Re: Worst case scenario
The last time I flew with BA, there were two observable benefits over the Ryanair experience: they didn't start "boarding" until the plane was ready to board, so there wasn't a prolonged period of standing in a corridor after scanning your boarding card waiting for the incoming passengers to disembark and the plane to be cleaned; and we were the lucky recipients of two small complimentary biscuits. The problem is there are only a very limited number of ways in which you can differentiate the process of sticking people in a big tube and firing them to a remote destination and they come at a cost that might be disproportionate to the added value for many people.
There are people who are prepared to pay very significantly more for a relatively more "luxurious" experience, but the premium cabins wouldn't be fully occupied without also being offered as a perk for frequent flyers (though BA has recently changed its scheme in the hope more passengers are actually paying for the privilege) and you can't fill an aircraft with them on most routes. There have long been flights that operate two different brands and fare structures on the same aircraft (e.g. Iberia/Vueling and formerly Sabena/Virgin) and you could possibly see that developing into a branded service at the front of the aircraft and white-label bus seats at the back. But that doesn't depend on AI, it's simply the economic inevitability of an increasingly perfect market.
The criticism often leveled at BA is that it is neither one thing nor another - its economy service is basic but not cheap and its premium service is expensive but inferior to its competitors. Maybe crunching all that data will at least help it decide which market it's trying to serve.