The first build goes out on Friday, August 28, around 6 PM CEST. As mentioned when signups opened, players come in in small waves rather than all at once, so if you are not in the first group you have not been forgotten. The waves grow as the build earns it.
What you get is an early work in progress version of the open Caribbean. 200 AI captains sail, trade and fight on their own, whether you join them or not. Expect rough edges, that is what a playtest is for.
What we want to know is how the game runs on your machine, where the first hour confuses you, and which moment made you stay. How to report bugs and share feedback is explained right in the build.
There is no NDA, so talk about it wherever you like. Everything that comes back goes straight into development, and there is still time for it to change the game.