Unless I’m missing something, the Reddit discussion seems to indicate that the only maintained versions are the ones maintained by Ultralytics. Are there other maintained versions out there?

Even if this is not the case, that doesn’t mean the article is a ”total scam”.

Yes it is a scam because it says that YOLO is ultralytics. That's the wrong point. There are hundreds of different YOLO implementations. Just search for some bookmarks or look in huggingface. Paperswithcode is dead now, hugging face built something similar.