Not at all. The only similarity is that LLMs work with text, and the document formats can also represent text.

Each format (E.g pdf, json, excel) has a defined standard, so all you have to do to change between each other is to map one format's fields to the others. You don't need (and won't get good results) from having an LLM produce the new format from scratch.

What he's asking is the equivalent of asking if there's an LLM made specifically for solving arithmetic problems. Why would you try to solve addition using an LLM?