For what ever reason (rumors Abound as to why) Thousand Trails/Leisure Time/NACO parted ways with ROD but, that was the loss of many parks. The next big player is probably Western Horizon Resorts who is slowly selling off their parks to companies who are not membership parks so these parks are withdrawn also. Other than that I am unaware of any great exodus of parks from the system.
I am sure they would like to find other parks to add since the loss of parks makes membership in ROD considerably less appealing than it has been in the past.
Brian, Loretta & Daisy (Golden Retriever)
2008 Holiday Rambler Endeavor 40 PDQ , ISL 400
2014 Ford Explorer toad