> an LLM can ingest unstructured data and turn it into a feed.

An LLM can try to do that, yes. But LLMs are lossy compression. RSS feeds are accurate, predictable, and follow a pre-defined structure. Using LLMs to ingest data which can easily be turned into an parseable data structure seems strange: use the LLM to do the "next part" of the formula (comprehension, decision making, etc)

There is also LLMs.txt https://llmstxt.org/ eg https://joshua.hu/llms.txt / https://joshua.hu/llms-full.txt