Most of the focus on this isn't the code. It's the art and music that make up the experience.

This is discussed right in the article.

> For Kanaris-Sotiriou, the question of adopting the use of gen AI to make games was an easy one to answer. “The foundations that it’s built upon, the idea of using other people’s work without permission to generate artwork [...] are unfair,” he says.

I personally think using AI assistance for the code is much less intrusive than using AI for the art and music -- the code isn't as directly experienced by the player as the art.