I've finished updating the blog, which changes the URLs of all existing posts making them shorter. I have updated Disqus with a new URL map and setup redirects in place for the old posts which already had comments posted on Disqus before all the URLs were changed over.
I noticed that Disqus doesn't really update the old links when you look at the "also on wainuiomata online community" section below the comments and it doesn't really update the old post titles either, as I had also changed these earlier, but with the redirects in place everything still works fine including the old links to posts.
New comments added after this point should come up with the proper post titles and new URLs.