In the latest shareholder meeting, Elon talked about not wanting to shove too much new technology into the 3 like they did with the X. At the same time, he talked about putting new technology in the S and X lines first (largely due to high cost on first iterations, though probably also so it can be tested on a smaller audience first, though they won't likely say that in public).
So....if there is ever to be autonomous driving, I would expect to see it in the S and/or X first. And then maybe it will make it's way to the 3 a year or two after that. In other words, no autonomous driving for the 3. At least, not at first.
You can read just about anything into the "doing the obvious thing" comment, as what Elon finds obvious, many others will not. I might think the obvious thing would be to drop the electric drive train for the 3 and use a gas engine. Obviously, I don't really think that. Or do I? You don't know!