"AI is not the default" is not a claim made anywhere AFAICT, especially not with that wording. The only thing you could be referring to is the explicitly no-ai url, which AFAICT has no "Auto-Generated" "Search Assist" (that's kinda the point), and it also hasn't used that phrase ever that I've seen in months.

So I kinda feel I have to ask: did you read the article, or did you read an AI summary?