There are 2 assets some may not be aware of that can be used to avoid links to sources that have address changes, which is a constant problem, or worse yet, removed from the web, altogether. One is the cache version. I find that through a google search by adding cache to the name of the page or simply peeking inside the search result I'm interested in. In the desired search result item, click the 3 dots on the right, then in the pop up box, click the down arrow. If the page has been captured, you will see the word cache and that link takes you to the page as google memorialized it on a given date (shown at the top of the page). Another method, if a cache version isn't found, is to create one yourself through the WayBack Machine owned by Internet Archive. As long as the site allows crawlers, this tool, shown on the right will create a snapshot and give it a permanent address.
For our clever developers, on the left is a link to the code for an Availability JSON API that, when run, gives the latest archived snapshot, if available. Links from Internet archive, familysearch, and other large entities won't likely need an archived page but any personal website and pages that are in danger of being swallowed by ancestry.com would be protected through the cache or archived page.
WayBack Machine Chrome Extension
ETA: Correction, Google cache will be replaced when they crawl the page again and is temporary.