From Few weeks it is visible that layer of Wikipedia has been dropped by Google Maps from its list of various other layers. There have been a pile of complaints gathering up in a Google Maps Help thread regarding this Drop out.
Layer was about extra content and information provided by Wikipedia about a specific location about which Wiki used to have any kind of data. Now, any such kind of information is gone.
Even in the help document giving detail of various layers, the name of Wikipedia is removed from list of layers. At the moment, name of layers goes as
Google have not put on its official statement regarding the ever going pile of complaints on its Help forum and threads but as far as statement from reality is concerned, days of Wikipedia from Google maps are gone and it’s kind of official.
Forum discussion at Google Maps Help.