Dona Sarkar is at it again, tweeting just now that a new build, 16237, is incoming. The Windows Insider program usually has two daily release windows, at 10am and 3pm PT, so we're expecting this one in about 45 minutes from now.
— Dona Sarkar (@donasarkar) July 7, 2017
Late yesterday Microsoft released a cumulative update for Windows 10 Insiders on the Fast Ring, but it was only used to test the servicing pipeline. You won't need to install the CU to get today's update, which we're expecting to be a full Windows Insider Fast Ring build.