If we're following the chess analogy the developers are allowed to use AI to train their skill but not to aide in the actual competition.

I don't understand your argument at all. Your first comment seems to disagree with the ban, but this one explicitly agrees with it.

Your example is weird because it doesn't exist. There is no restrictions on how chess players train, only how they compete. All you're doing is building a strawman, not an analogy.

And to be clear, they didn't get banned for using AI. They got banned for lying about using AI. You can agree or disagree with the rule itself, but it's not debatable whether it was in place when they entered the contest or whether the studio lied about it.