There is a "closedown" process in progress.
1) First, the old online manual site was THE docs site, and the new online site was just a beta
2) Once the new online manual was ready, we gave Sleepy a bunch of information connecting old docs with new ones.
3) Currently, whenever the SMF program takes a user to the old docs site (the search in the admin center), they see the old article, with a link telling them they'd be better off with the new one
4) In the future, going to those OLD site URLs will cause an instant redirect to the specified document on the NEW online manual.
At the moment, that's what the obsolete doc site is for.