Microsoft today released a late-afternoon cumulative update today for PCs in the Release Preview rings of the Windows Insider Program today. KB3176938 brings the build number to 14393.105.
In case you've got some type of photographic memory and KB3176938 looks familiar to you, that's because it is. It's the same KB number as was seen in the last cumulative update that Insiders got, 14393.103, which was for PC and Mobile. Today's update does not have a counterpart for Windows phones.
The last update to hit the Production ring (non-Insiders) for PCs was 14393.82, which broke PowerShell DSC. At the time, Microsoft promised to have a fix available on August 30, which happens to be today. That update wouldn't happen as planned.
It was assumed that today's update (had it been released) would have been 14393.103. Presumably, the company found a bug in last week's cumulative update that prevented it from being shipped to non-Insiders, forcing today's 14393.105 release.
There is no changelog available yet for today's update, which isn't entirely surprising. It's likely, however, that it's almost the same as 14393.103 was, since it has the same KB number.