Just in case anybody wants to read a bit more about this: This is Green Open Access, which usually means that the publication is blocked for a while, but usually doesn't cost the author (or their institution) anything extra. The other option is Gold Open Access, which, depending on journal, can get rather pricey, but makes the article openly available immediately.
Yes. Science and Nature are different in this regard. Science also has much lower subscription fees, probably because it's run by a nonprofit, where Nature is for-profit.
