This may seem impossible to anyone watching GSN nowadays but it's true, certain seasons of Richard Karn and John O'Hurley-hosted Family Feud have departed from the schedule, possibly permanently.
Though I haven't heard anything, the 2002-03 (Karn) season and both the 2006-07 and 2007-08 seasons (both O'Hurley) have been exiled from the GSN Schedule and have stayed off for the past three months.
It would make logical sense the first two O'Hurley seasons to drop off the schedule, since they did come from the same lease at the same time. The O'Hurley version has always been the lower-rated modern Family Feud, though more recent numbers shown an improvement over the Richard Karn version. The only seasons of O'Hurley Family Feud on the schedule lately have been 2008-09 and 2009-10. Who knows where the first Karn-hosted season has gone but it's been a cast away for the longest time now.
Currently on the schedule, Richard Karn's Family Feud has three cycles (5pm weekdays, Saturday, Sunday) while the O'Hurley version has four cycles (1pm weekdays, Monday nights, 5pm Saturday, 4pm Sunday).
All four seasons of Richard Karn's Family Feud were added to the GSN schedule in 2007. John O'Hurley's first two seasons were added in 2008, with his third season in 2010 and O'Hurley's fourth and last season came along in 2013.
Most of this information has been obtained due to the advanced schedules at GameShowFollies.