If you're an Insider running the Windows 10 Mobile Preview builds, you might want to double-check the status on your phone. First spotted by Daniel Rubino of Windows Central, it would appear that some users are finding that their preview status has been reset.
Indeed, three of the six phones that we use for Insider Preview testing were found to have removed themselves from the Insider Program. Interestingly, upon adding them again, they were already set to the rings that they were previously in.
Earlier today, Microsoft finally released the Windows 10 Mobile Anniversary Update, so with the exception of carrier-locked phones, any Windows 10 phone should be running the AU. Later, the company would offer a cumulative update through the Release Preview ring only, build 14393.82, so it's quite possible that the firm is gearing up for a new Fast ring offering soon.
To check your phone's status, head over to Settings -> Update & security -> Windows Insider Program. If you see a "Get Started" button, tap it, follow the prompts, and restart your phone. Once it reboots, revisit Settings and make sure it says that you're in the desired ring.