I doubt their was much strategy to the release other than the Wii U failed spectacularly and 3DS sales were slowing, so it was time to release. Where Nintendo played it smart was seeing the dwindling handheld market, acknowledged that they couldn't compete head on in the home console market, so combined their efforts into one hybrid platform. It was a different enough experience that it really isn't in direct competition to the PS4, so each ones sales aren't really affected by the other.