The GPL family of licenses was designed to cover code specifically. AI engines are code and are covered in most jurisdictions by copyright. (Disclaimer: I know a lot less about international intellectual property law than about U.S. intellectual property law. But I'm pretty confident what I'll say here is at least true of the U.S..) But you don't really have a functional generative AI system without weights. And it's not clear that weights are covered by any particular branch of intellectual property in any particular jurisdiction. (And if they are, it's not clear that the legal entity who trained the engine owns those rights on those weights rather than the rights holders who hold rights to the materials being used as training data.) It's the weights that would make for any biases or purposefully nefarious output. Nothing that isn't covered by intellectually property can meaningfully be said to be "licensed", really. Under the AGPLv3 or any other license. To speak of something not covered by any intellectual (or non-intellectual, I suppose) property as "licensed" is just kindof nonsensical.
Like, since Einstein's General Relativity isn't covered by any intellectual property, it's not possible for General Relativity to be "licensed". Similarly, unless some law is passed making LLM weights covered by, say, copyright law, one can't speak of those weights being "licensed".
By the way, there are several high-profile cases of companies like Meta releasing LLMs that you can run locally and calling them "Open Source" when there's nothing "Open Source" about them. As in, they don't distribute the source code of LLaMa at all. That's exactly the opposite of "Open Source" and the weights aren't code and can't really be said to be "Open Source". More info here.
Now, all that said, I don't think there's actually any inherent benefit to LLMs, AGPLv3 or otherwise, so I don't have any interest even in AGPLv3 engines. But I'm all for more software being licensed AGPLv3. I just don't think AGPLv3 is a concept that applies to any portion of LLMs aside from the engine.