You're the new guy. You look for documentation, you find something outdated, untouched for 6 years with a note that the page was migrated from some other system and is "work in progress".
If that thing was untouched for 6 years, it is logical to conclude that it no longer contains correct information. You read a few lines, see dead links and wrong information, you conclude that it is no longer useful.
The person that wrote the original wiki, still works at the company, but they now work on a different system and have no responsibility for that legacy system.
See, the issue is always the same: transfer of knowledge deteriorates with every person that quits or gets promoted. The system is now maintained by someone else, who has their own "wiki" on their own machine. The original, now useless wiki, should have either been deleted or updated. This doesn't happen.
This creates such waste on a global scale, that it is beyond comprehension. Whoever solves this issue, will surely help the human kind.
In summary, when a transfer of ownership for a wiki occurs, there should be a mechanism to make sure that it gets either deleted or maintained. Having new hires hunt for information, benefits no one, especially not the organization. Get your documentation in order, and you will save a ton of hours and improve productivity!