User blog comment:Rappy 4187/Technical Update: September 7, 2015/@comment-24473195-20150909130617

I've noticed that special:Insights seems to have started working in some wikias, but not others. For example this wikia still has a blank Wanted pages which is practically impossible (see Special:WantedPages) given that nobody maintains those dead-end links. Maybe the cache is expiring in different wikias at different rates.