Originally Posted by IOWA
If you're rooted, don't accept the update if you plan on keeping root. Predictably it does break root, and there are unconfirmed rumors of a locked bootloader.
I'll keep this post updated about the OTA as I learn more.
UPDATE: So far so good. It appears both rootable and the secure boot has something to Do with knox.
More info the link posted below this post by jhawk. Waiting for more confirmation before I take down the PSA.
UPDATE2: How to update and keep full root