If your docs and PR descriptions can be generated off file diffs everyone's time could be better spent scanning the diff to come to the same conclusions.
Consider using your PRs and docs to capture the answers to the usual why questions which LLM won't be able to do.
I've seen code bases survive three different ticket management systems. Meanwhile, the tickets never made it between the different systems, so if the 'why' isn't in the commit message, then it got lost to time.
I will admit that a lot of the really old decisions don't have much relevance to the current business, but the historical insight is sometimes nice.
Consider using your PRs and docs to capture the answers to the usual why questions which LLM won't be able to do.