Microsoft today introduced a new Release Preview ring for the Windows Insider program. The Release Preview ring will allow users to stay on Threshold 2 and continue to get updates for build 10586. Microsoft will continue to deliver Redstone builds to Insiders, which means users will have to use the Release Preview ring to stay on Threshold 2 and get a better user experience. The Release Preview program will allow users to get (early) access to patches for the existing build (10586).
If you don’t want to stay on Threshold 2, you can simply go back to the Fast or Slow ring to continue getting the latest builds of Windows 10.