Apple iPhone SE Black
Apple has released iOS 13.4.1 for the iPhone SE today. Ironically, anybody who pre-ordered their iPhone SE should be receiving them tomorrow, so you should expect the OS to be upgraded as you set it up.
iOS 12
Apple has released iOS 13.4 which focuses on bug fixes. Most notably, they address a problem caused by iOS/iPadOS 13.4 wherein users running that version could not join FaceTime calls with users running older versions of iOS or macOS—iOS 9.3.6 or OS X 10.11.6 or earlier, to be specific.