[Correction- Deep Fusion is available in the iOS 13.2 beta, not 13.1.2. I just happened to be waiting to update to 13.1.2 when I saw reports that the beta with Deep Fusion had released. While some reports say that 13.2 has been released, it is not available on the Apple Developer Page yet.]
Apple’s new Deep Fusion photography mode has arrived early for the new iPhones 11, 11 Pro and 11 Pro Max, courtesy of the iOS 13.2 Developer Beta that was released earlier today. Based on this quick follow-up to iOS 13 ans 13.1, it seems that Apple is handling this new photo enhancement mode similar to how they approached Portrait Mode a few years ago, likely targeting a mid to late Fall release.