Prob just a random date they picked since the official date haven't been announced yet.

Oh and if anyone is wondering I ordered my PS4 like a day or two after the e3 announcement and I had to order the standard edition which is the same but just means I couldn't get it on launch day. Amazon emailed me this weekend and said they bumped me up to launch day because they're going to get more than they initially planned.

Still hope for people that ordered late