Tucked in yesterday's post about Android Support Library v23.2 were a couple of screenshots, posted on the Android Developer's Blog, of an unreleased Android version. How do we know? Because there's a hamburger button in the Bluetooth settings section, a button that doesn't exist on Marshmallow, but that we're able to confirm is there on Android N.
This hamburger button does what hamburger buttons do: it opens the side drawer. The drawer has a list of all the settings sections so instead of going back to the main settings screen and choosing one, you can simply open the drawer, tap a new section, and jump to it immediately.
It's arguable whether that's faster or not, but what's even a little more jarring is the fact that the drawer won't exist in the main settings screen — it would be redundant. Google has been adamant about developers making the drawer a constant across their apps, not something that's accessible from one screen and not from another. But it wouldn't be the first time it broke its own rules, so it could easily go with a navigation drawer that's only accessible in settings sections and not the main screen.
In any case, given Google's track record with Android M Previews, we know the company could be testing something for a while and not implementing it in the final version. That might be the case here or the hamburger button could live on through to the final N. Only time will tell.