Microsoft just released Windows 10 Insider Preview Build 18342 in Fast Ring. This is the version in the 19H1 development branch that we expect to receive in April 2019 as Windows 10 V1903.
The announcement and a description of the new features can be found in the Windows Blog. PCs with the following processor model numbers will not receive this build due to a Connected Standby issue: Intel64 Family 6 Model 142 and Intel64 Family 6 Model 158.
Microsoft has introduced some improvements in gaming. There is also the chrome extension for Timeline from the Chrome Web Store.
Linux files in the File Explorer
This build also allows users to access Linux files in a WSL distro from Windows. These files can be accessed from the command line, and Windows applications such as File Explorer, VSCode, etc. can also interact with these files. You can read more about this here.
More details about improvments and know issues may be read within the Windows Blog.