I agree that London needs more mappers. 

I was told very early on that people should only update the map if they have surveyed what is actually there (unless the change in use has multiple sources). Otherwise I could just have deleted the POI myself 2 years ago! I was told that the point of notes is to highlight things that are wrong so that it is clearer when areas need a resurvey. 

The map here is still not right so personally I think that the note should stay open until someone has surveyed what is there now.