User blog comment:Western Gen/Speculations for Season 12/@comment-75.183.74.92-20140124153813/@comment-4616231-20140124210433

Flowers was always intended to be a cameo character because his voice actor isn't around much (think he lives in like... Canada). Cameos are really the only thing he'd be around for, and bringing him back is just inviting him to be a main character, which doesn't really work with his VA's schedule.