Microsoft have wrapped up the development of Redstone 4 which is now officially called the Windows 10 April 2018 Update so it is a good time to check your Windows Insider settings. Starting as soon, maybe as soon as today Microsoft will be pushing Redstone 5 builds to the fast ring. For the last couple of months Microsoft have pushing Redstone 5 builds for Windows Insiders using the Skip Ahead option with the main change to the OS being Sets (tabbed Windows, see my video). As its early in the development cycle for RS5 you may want to step away as the builds can be buggy.
If you are happy with testing Redstone 5 you don’t have to do anything, if you want to keep with Redstone 4 you can change your Windows Insider setting to Release Preview.