For a day or two, members of the Windows Insider Program are in that special limbo period that lets them opt out of the preview program without having to reinstall their operating system from scratch. At the same time, anyone not in the Insider Program can now get early access to the May 2019 update, build 18362.30.

For most of the year, the only way out of the Insider builds is to reinstall the previous stable Windows release. But twice each year, there's a short period where the Fast and Slow rings are shipping the same build as will be used for the stable release of the twice-annual feature updates. During this time, users of the Insider builds can drop out of the Insider program entirely or switch to the Release Preview ring, and their systems will update to the stable release and then stay on the stable track from that point onward.

Microsoft will soon close the window by distributing a build of Windows 20H1, the preview of the first 2020 update, to the Fast and Slow rings. Once this happens, dropping out of the preview scheme once again means reinstalling from scratch or waiting until 20H1's eventual stable release next year.

The company does still intend to have a 19H2 feature update and will distribute builds of that to Insiders later in the year. However, the company has thus far said nothing about what this release will contain, leading to some speculation that it will have its features announced at Microsoft's Build developer conference next month.

Conversely, now is the moment for non-Insiders to get their hands on the May 2019 update before its formal release next month. The Windows 10 Release Preview ring is now distributing the May 2019 Update. It's possible that the build will need to be patched over the course of the next month, but there won't be any need to repeat the lengthy upgrade process that's used to install a new feature update. Aside from offering each feature update a few weeks early, the Release Preview ring is pretty solid, containing only builds that Microsoft believes to be good enough for mass adoption.