No, only people who pre-ordered are getting early-access. It's just that 3-4 day jumpstart. Not that much of an advantage, but noticeable for some.

The main reason SE is doing this though is lower server stress. Only people with pre-order and MSQ finished will be able to enter Ishgard, while the rest will have to wait outside = the instance server won't get hit by 100% of eligible players on day one. One part will hit it on Friday, and the other on Monday.