It is time to begin obsessively checking for updates on your 2013 Nexus 7. We're getting lots of reports of a system update to JSS15R hitting devices. Nevermind that there don't appear to be any user-facing changes, and it's only one letter away from the last minor update – this is new software and you must have it immediately, right?
The update clocks in at a whopping 8MB. The update notification just rambles on about Android 4.3 features.