Can someone explain why Star Wars Iphone games go missing?

There have been many Star Wars games for iphone; a Hoth tower defense game, a Stormtrooper Academy FPS, a Falcon gunner AR shooter, and a Cantina management game, to name a few . I name these few particularly because none of them are in the App store anymore, without explanation. I lost my iphone half a year ago, and when i replaced it was unable to retrieve them. Is it due to expired licenses or something? It's just sad because, not having a physical form like a cartridge or CD, once gone, these games are gone forever.