iOS 12.1 will unlock Dual SIM and Group FaceTime - but only for newer devices
Apple is reportedly not far away from unveiling the next version of iOS, which it may do at the upcoming launch event for the iPad Pro 2018 and new Macs (or so it is thought). This version, 12.1, may fix the widely-discussed "Beauty-gate" issue among other new tweaks and features. More specifically, fresh leaks indicate that it will bring Group FaceTime to iOS. It may also support the dual SIM capabilities of phones such as the iPhone XS.
Group FaceTime does more or less what it says on the stainless-steel container: it is FaceTime for more than 2 callers at a time. In fact, Group FaceTime may support up to 32-way video calling. However, it seems this new feature is only coming to newer iPhones and iPads. A 12.1 User Guide dug up by 9to5Mac lists the devices cut out of this feature: the iPads Mini 2 and 3 and the iPad Air. In addition, the iPhones 5s, 6 and 6 Plus will get a form of Group FaceTime, but without actual video.
In better news (for some), iOS 12.1 will also make the dual SIM slot found in newer iPhones operational. These devices will then be able to support 2 different phone numbers and their respective comms apps (e.g. iMessage). However, the second SIM in question will be the e-SIM that may only be offered by certain carriers.