I don't think that would bring much to the table in practice.
Firstly, as we've discovered, even constructing meaningful cards is difficult. Secondly, as we've discovered, making a computer play Dominion well is difficult. It's not easy to be in a position to have a computer design cards and playtest them.
But more importantly, making cards that are legal and balanced is only part of the battle. Cards also have to be different, and interesting, and fun. Ideally, they're also thematic, and introduce entirely new game mechanics.
Without those considerations, we'd be flooded with new card ideas like "Blacksmith: Action $4. +3 Cards. Discard the top card of your deck." or "Boring Village: Action $3. +1 Card. +2 Actions. Each other player may gain a Curse." They're not existing cards but, I mean, really... (-8
There are a lot of other really disruptive skills computers are going to acquire long before one can take the rules PDF for the Dominion base set, churn for an hour and spit out something as fun, innovative and high quality as the Adventures expansion. Donald X. has rather more job security than doctors and airline pilots.