@MarkZablocki ...
Unfortunately, you won't be seeing a reply from @kmeeusen any more here in the Community...as he has retired. But, I can answer your question. In Kelley's response from January 2020, he provided a link to a Guide from when the Canvas Community was using a different platform to host all of their forums, written and video tutorials, etc. The platform you and I are using now is different, and thus many links changed. While many of the links did migrate and re-direct, you stumbled upon one that did not. Thankfully, if you know what the name of the Guide title is, you can use the Search bar at the top of any page to type in the name of the Guide, and you'll most likely find a new link that will work. That's what I did with the link you are asking about. You can find a working link here:
How do I weight the final course grade based on assignment groups?
I hope this will be of help to you.