I think you've conflated two very different things.
The community rejected AI content being merged inline with human content. And it did this for very good reasons. It especially rejected AI content maskerading as human content by way of users and bots posting it as if humans were authoring the answers.
The feature you're pointing to is not injecting AI generated content into a space for user written content and it is not expecting the moderators / curators of the user written content space to also moderate and curate the AI generated content.
Neither is it blurring the boundary between the two spaces such that readers are unaware of the division between user generated content and AI generated.
I don't believe it's wise to deny that LLMs have a part to play in helping people learn. This would be as nonsensical as to suggest Google Search has no part in people's learning (AI driven since 1998). Of course there are many well documented dangers from simply trusting LLMs but, in the right hands, LLMs are a really powerful tool for accelerating learning.
LLMs are undoubtedly changing the way we code and they look set to change a lot of things in life over the next few years, but the technology is still in its infancy and people are still learning what it's good at and frequently making mistakes.
Ultimately the world is changing and LLMs will be a larger and larger part of a developer's life. SO can either try to experiment with new and innovative ways to use them or it can stick its head in the sand and pretend the world isn't changing.
No we don't want AI content on SO Qs and As. But that's a different topic than suggesting SO can't have AI on the site at all.