It must be a daunting chore to maintain all the legacy pages. The amount of now-years-old stuff that long-standing sites have to maintain, or choose to maintain, is shockingly high, and testing the combination of all that stuff is impossible.
One company I worked for used interns and new hires for that. One of the early tasks assigned to the intern pool was to comb the web sites for outdated information, or things that no longer conformed to the current brand book. The list then went somewhere else so the pages could be updated or deleted.
The major benefit of this was giving the new people an overview of what we do, why we do it, and a slice of the history of the products.