https://www.bleepingcomputer.com/news/microsoft/windows-10-insider-preview-build-18342-released-with-numerous-improvements/

Microsoft has released Windows 10 Insider Preview Build 18342 (19H1) to Insiders in the Fast ring. This build adds numerous Windows Sandbox fixes, changes to gaming, and the ability to access WSL files in File Explorer.

Microsoft has stated that this build will not be offered to PCs that are using the PCs with the Intel64 Family 6 Model 142 and Intel64 Family 6 Model 158 chipsets due to an issue with Connected Standby.