Because SEGA has lost the rights to sell Virtua Tennis 2009 anymore, OnLive has removed the game from the marketplace where it was sold as a PlayPass, and OnLive has also removed the game from the PlayPack. If you own a PlayPass to Virtua Tennis 2009 on OnLive, you can still access it, and will be able to do so for the foreseeable future. Because Virtua Tennis 2009 was removed from the OnLive PlayPack, the PlayPack lost one game and is now at 252 games and counting.
OnLive senior manager of customer relations Nathan Barsetti wrote this at OnLive Fans: "Let's talk tennis. Turns out, SEGA has lost the rights to sell Virtua Tennis 2009 anymore. This impacts our ability to sell any new PlayPasses of the game, or to include it as part of the PlayPack. It is important to mention that if you own a PlayPass of the game, you can still access it, and will be able to do so for the foreseeable future."
Though OnLive Founder and former CEO Steve Perlman said that he liked more historic games like the Assassin's Creed series, Steve used to demo the hell out of Virtua Tennis 2009 on various presentations and it was a long running joke that it was his favourite game. So it's only a fair completion of the joke that now when he's gone, his beloved game is also gone.