Windows 10 1703 Redstone 2 is looking for March or April release. WalkingCat has spotted references to the “Version 1703” in the latest Redstone 2 Insider build 14946. This confirms that Windows 10 1703 Redstone 2 is heading for March/April release.
Previously, Microsoft announced that two major updates for Windows 10 are coming in 2017. Third major update for Windows 10 codenamed Redstone 3 is coming in summer of 2017. Microsoft is also planning a single major update in 2018 as Redstone 4.