Last week, Microsoft pushed Windows 10 May 2020 update to the Release Preview ring, and now it releases another minor build to the Slow ring only. The Build 19041.208 (KB4558244) comes with a fix for the issue which fails to send NPLogonNotify API notifications from the credential provider framework.
As this build is not released to the Release Preview ring, Laurent Giret of Onmsft asked Senior Program Manager of Windows Insider Program Brandon Leblanc the reason behind not releasing it to Release Preview ring, which in return he answered that they are testing the update first in Slow ring before rolling it to the Release Preview ring.
However, the issue with the latest release of Microsoft Edge based on Chromium for Narrator and NVDA users persists and may face some difficulty while navigating and reading certain web content.
This build also includes the fixes which were released last week in build 19041.207. You can check the release notes of the build 19041.208 (KB4558244) at Windows Blog for more details