AI, but I'm not sure about "slop". There is actual content in there, for all it's written by an LLM.
Where LLMs can be really actually quite useful, is situations where you have a lot of context and want to distil it. That's what I think happened here: the author has a lot of information to convey, and the LLM-generated output is relatively information-dense.
Unfortunately there's no objective measure for information density of an arbitrary piece of text.