Microsoft has just announced the availability of Windows Server vNext preview build 18975 and Windows 10 SDK Preview build 18975. Both updates follow the release of Windows 10 20H1 build 18975 for Fast Ring Insiders last week.
Once again, the new Windows Server build brings no new features to the table, and the release notes mention the same single known issue related to App Compatibility FOD that was mentioned for the preview build 18965 of the server OS two weeks ago. As for the Preview SDK build 18975, it brings the usual API changes for developers, but the rest of the release notes are copy pasted from the previous blog post for the SDK build 18970.
As usual, you can download the new Windows Server build from the Windows Server Insider Preview download page. As for the new SDK, it's available from the developer section of the Windows Insider website.