Maybe its not been updated because it does not particularly need it ?
It has one dead link (Object Pascal Tutorial) and perhaps does point to some older pages but just scrolling through it now I felt it worth bookmarking. Its quicker to find the things I look for than is the Official page.
On the other hand, I absolutely agree that out of date pages should be removed and meta pages, all the more so.
But it does strike me as useful and, maybe if renamed as you suggested, "Site Map", could be more so. It would need to tread the thin line between not being maintained and getting too big. But thats the very nature of wiki isn't it ?
I'd add a link to Installing....
Davo