We’re still waiting for the next Windows 10 update, probably to be named the April 2018 Update, even though April is rapidly nearing its end. This means that the Fall Creators Update, Windows 10 version 1709, is still the latest update, and hence, it’s still creeping upward in usage.
The numbers also suggest that Windows Insiders may be a little more diverse than expected. Most months, the number of people on the next version of Windows is about 0.4 percent. But in the months immediately prior to a new update—during which the putative release is pushed out not just to the usual Fast and Slow distribution channels but also the Release Preview channel—that number hits about 0.8 or 0.9 percent. This doubling of the apparent size of the Insider program suggests that there’s a surprisingly large number of Insiders that are using Release Preview builds, not just wanting to use the previews unless they’re close to production ready.
The April 2018 Update itself now looks likely to land in May. Microsoft tends to release updates on Tuesdays, and we’re all out of Tuesdays this April.