URLs from substrate.io are quite useful and we suspect them to high a lot of traffic and clicks. But, most are not maintained, outdated, or wrong.

What we should do is:

1. For all pages, include a fixed banner that indicates when this page was last edited. This should give a good idea if this page is already out of date or not.
2. For pages that are going to have anew equivalent, add a banner that explicitly forward the user to the new page.

This is much better than a blanket redirect. A blanket redirect can be implemented in eg 1 year.