Gabriel Aul is one brilliant man is believed to workaround the best of things for the insiders. If his tweet this morning is to be decoded, then it seems that it is highly likely Microsoft is going to roll out Redstone.
There is an update being rolled out as "Configuration Update" for the Fast Ring Insiders is being pushed to support a certain updates along with preparing the device for the upcoming next Firmware OTA.
"Today we are rolling out a Configuration Update to the Windows 10 Mobile Insider devices in the Fast ring. This update prepares devices to receive the next cumulative updates, as well as improvements to the client-side update experience. There are no noticeable changes immediately after installing this Configuration Update."
If you're a fast ring insider, then wait for the notification to hit your action centre or hit "Settings", search for Phone Update and Click Search for Fresh Updates. The update seems to be a smaller one, no no such changes mentioned but that eventually means that this is a preparatory update for the next major update which could be the Redstone Firmware.
Guys, hit out to the update and tell us if you note any more changes in the comments section below, We would be glad to cover them in and give you a mention in the sources. :)