My bet is it's a fine-tune of an existing pretrained model that was later fine-tuned on his artwork. Would this resolve as No?

 That’s exactly the situation that I figured, and would resolve YES since it was at some point trained on non-Kaneko (or bootstrapped) content.

Extending resolution time in order to give information more time to come to light after the game's release.

a new game featuring procedural image generation. He claims that the model was trained on a set of images bootstrapped from his artwork. The typical method for creating style-specific image models involves fine-tuning general-purpose models that have been trained on very large corpuses.

This market resolves YES if any version of the system shown in marketing or used at game launch was trained on content that was not either drawn by Kaneko or bootstrapped from a model starting with only Kaneko's work as input.

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