A mere two days after iOS 10.1 beta 4 and just over a week after the macOS Sierra 10.12.1 beta 4, Apple has just released the fifth beta versions of both.
IOS 10.1 is now in its build 14B72c (this is apparently only available for iPhones 7/7 Plus, as well as iOS 10.0.3), while macOS Sierra 10.12.1 is on 16B2553a. Both are already available OTA (over-the-air, that is, over the air), through the Apple developer portal and also in the Apple Beta Software Program.
On a related note, Apple today stopped signing iOS versions 9.3.5 and 10.0.1, preventing users from making downgrade for them, as well as for the fourth generation Apple TV tv.2 9.2.2.
Update · 10/20/2016 s 15:02
A day later, Apple just made available to developers also the tvOS 10.0.1 beta 4 (compilation 14U71).