There seemed to be more plan for Flair in 2011 , but he suffered that arm injury against Sting and he went on the shelf soon after and just played a minion to Hogan at the end. In 2012 he came back but wanted out as we know.
In listening to a JR Podcast deal what led Flair to leave the company in 2008 after the whole retirement deal was that he was doing indie dates for people as well. Well the NWA after seeing Flair go into WWE Hall of Fame contacted Flair for the NWA Hall of Fame and it made sense. Flair was a 6 or 7 time NWA World Champion. He is known for his 80's peak of greatness.
Vince got mad at this idea and blocked Flair from doing an appearance at this Hall of Fame. So Flair let his WWE contract run out and later did the appearance. But Jim Ross said that added to Flair's issues with company.