Quote Originally Posted by LdyZanguya View Post
"What is Early Access?
Get immediate access to games that are being developed with the community's involvement. These are games that evolve as you play them, as you give feedback, and as the developers update and add content.
We like to think of games and game development as services that grow and evolve with the involvement of customers and the community. There have been a number of prominent titles that have embraced this model of development recently and found a lot of value in the process. We like to support and encourage developers who want to ship early, involve customers, and build lasting relationships that help everyone make better games."

And thats just from Steam because they let developers do this. In a technical world usually that is the purpose of Early Access.
http://na.finalfantasyxiv.com/lodestone/topics/detail/7933cb4e7b3a01b4e86dc352c2ac06cca462cfc4#aa1

What is Early Access?

Early access is a pre-order bonus that will allow you to play FINAL FANTASY XIV: Stormblood before its official release on June 20, 2017.