Microsoft has today teased Windows 10 Mobile / PC Build 15063 as coming to insiders in Fast Ring. The tone and content of the tweet suggest that this may be the special one, the RTM sign-off build.

The Fundamentals team has plotted, planned, schemed, dreamed…and this evening a major heist is in progress for the Windows Insiders

The Build 15063 may be live soon and may be live for both or as expected only for Windows 10 first. Mobile insiders usually get the same RTM Build after days or weeks of PC insiders getting it.