The new regulation requires a hand-wavey style explanation i.e build a retrieval / ranking / matching algorithm that learns from customer clicks and considers blah blah.
There will be no explanation of the actual algorithm.
Probability ranking principle will never not be the foundation for recommender systems. Any statistical model flowing from PRP will be more or less the same regardless of whether the architecture is neural, boosted trees, etc.
However, if regulation required companies to disclose all of the data goes into those models, how they acquire it (tracking browser/app behavior, purchase from 3rd parties), and so on, that would be the real game changer for consumer privacy and protection.
No explanation - no market. If you don't like it, you can run your business in another contract jurisdiction. I hope these companies will taste their own medicine, we desperately need competition
There will be no explanation of the actual algorithm.