From the TfL bus changes page for 22nd February
68 West Norwood - Euston
To help maintain the reliability of the service during the improvement scheme taking place in Camberwell town centre a temporary timetable will be in place with the frequency of route 68 changed to every 9-10 minutes between 0700 - 1900 on Monday to Fridays.
means
68 West Norwood - Euston
To help maintain the reliability of the service during the improvement scheme taking place in Camberwell town centre a temporary timetable will be in place with the frequency of route 68 reduced to every 9-10 minutes between 0700 - 1900 on Monday to Fridays. (...because we're so skint we can't afford to add extra buses to the timetable to maintain current frequencies during the works...)