Just two days after Microsoft released the 19H1 build 18351.7 for Windows Insiders in the Slow Ring, Microsoft is releasing another minor update today in the form of the cumulative update build 18351.8. As a reminder, the build 18351 first shipped to Fast Ring Insiders last week, and this new minor update that is shipping to Slow Ring Insiders today only brings a "fix to improve how we service builds," the Windows Insider team explained.
— Dona Sarkar (@donasarkar) March 13, 2019
Overall, this is the third 19H1 build that Microsoft is making available for Slow Ring Insiders, but Microsoft has yet to fix issues related to anti-cheat software and Create X-Fi soundcards. These bugs are also still present in the builds 18356 and 18855 that Microsoft released this week for Fast Ring and Skip Ahead Insiders, respectively.
This fast release cycle should continue until Microsoft is finally done with the 19H1 update for Windows 10, and the Windows Insider team will also use the Release Preview ring to test drivers and quality updates ahead of the public release.