https://wccftech.com/windows-10-20h2-build-19042-508-kb4571756/

Microsoft has released Windows 10 20H2 Build 19042.508 (KB4571756) for Windows Insiders in the Beta and Release Preview Channels who are testing the upcoming version 2009 aka the November 2020 Update (not the official version number). The upcoming version is also currently in the pre-release validation phase for commercial clients.

Since both the Windows 10 version 2004 and the upcoming version share a common core operating system, they receive same set of monthly updates similar to last year's versions 1909 and 1903.