The feature was expected to launch alongside the release of iOS 12 and macOS Mojave later this fall, but unfortunately it seems to have been delayed. According to the latest developer release notes, Apple said, “Group FaceTime has been removed from the initial release of iOS 12 and will ship in a future software update later this fall.”
It should be noted that the release of iOS and macOS updates aren’t usually at the same time, so it possible that while it might not be shipped with the final release of iOS 12, it could be ready in time for macOS Mojave. Apple does not state the reason behind the delay but hopefully it won’t take longer than necessary.
Apple has in the past delayed features that were meant to be part of the iOS release, such as Portrait Mode for the iPhone 7 Plus, so this move isn’t completely unprecedented. Either way we’ll be keeping our eyes peeled for more information about its release, so check back with us at a later date for more details.