iMovie for OS X removed from OS X?
Apps don't disappear automatically. If you have iMovie '11 (version 9.x, gold + dark grey icon), the Mac AppStore will show the current version of iMovie (version 10.x, purple-coloured icon) as a new item because Apple charges for major version upgrades (e.g., version 9.x to 10.x), unless the user has a voucher from purchasing a new Mac.