It's been three weeks since Microsoft released Windows Server Insider Preview build 19008, so we're due for a new one. Today's build is number 19023, coinciding with the build number for the Windows 10 client build that was released last Tuesday.
As usual, Microsoft has released the build, but it hasn't published a blog post to say what's new. It's unclear why the company is unable to publish blog posts at the same time as the build itself, but it's safe to say that it will announce something later on today.
In the meantime, you can probably assume that there isn't anything new, or at least anything meaningful. Windows 10 20H1 isn't really getting new features at this point, and we're expecting it to RTM some time next month. This build likely only contains some bug fixes.
While Microsoft has been testing Windows Server 20H1 with Insiders, 19H2 has pretty much flown under the radar. It was released last week though, alongside of Windows 10 version 1909. Like Windows 10 client, it doesn't contain much in the way of new features, focusing on reliability instead.
If you want to download the new Windows Server build, you can find it here.
Update: Microsoft has now published a blog post for Windows Server build 19023. There is still nothing new.