AirPods Max Support
If you plan on buying Apple’s new AirPods Max over-ear headphones (assuming you can get your hands on them), you’ll need iOS 14.3 in order to pair them up with your iPhone (and by extension, iPadOS 14.3 for your iPad, watchOS 7.2 for your Apple Watch, tvOS 14.3 for your Apple TV, and Big Sur 11.1 for your Mac).
It doesn’t seem that iOS 14.3 brings anything particularly unique for the AirPods Max that we haven’t already seen with the AirPods Pro, just the same features like Audio Sharing, Announce Messages with Siri, Adaptive EQ, Active Noise Cancellation, and Spatial Audio, but the key is that you’ll need iOS 14.3 to make these things work with the new full-sized AirPods.