I think Yahoo fantasy sports and others in the space are doing amazing work on this idea. I wonder if an LLM is even necessary for this, it’s mostly maths. Analyze past winning decks and made decisions based on performance.
For learning to draft in one environment and then applying it to a new set of cards, like done here, it would become far more difficult to do without an LLM. The variations and nuances of cards rules text would have to be encoded as features, which would be extremely cumbersome. The LLM gets you some level of understanding of that for free.
MTGA and MO development team do a lot of work to put card effects into if-then rule, but unfortunately their work is not visible to the players :)