I remember when I was getting started with Django in the 0.9 days most of the assistance you got on the IRC channel was along the lines of "it's in this file here in the source, read it, understand it, and if you still have a question come back and ask again". I probably learned more about writing idiomatic Python from that than anything else.
I can confirm that that was the general mindset back then, and I think that's what made the project last for 20 years. I myself ended up doing some monkey-patching for the admin interface on 0.92 (or 0.91? it's been a lot of time since then), all as the result of me going through the source-code. Definitely not the cleanest solution, even back then, but it made one getting to know the underlying code so much more.
Sure, I thought, this'll be fun.
Holy shit. It was something I'd started working on in the aforementioned 0.9x days, and which someone else had, uh, "extended and modified" after I left the web dev place where I'd worked at the time. Remarkably it was still pretty understandable.
I didn't want anything to do with the person that ran the site, not even just to take money off them, so I passed on it.
I think it's perfectly doable to use an LLM to write into the Django codebase, but you'll have to supervise and feedback it very carefully (which is the article's point).