Yes, sorry, bad wording. You can download a Sublime Text 3 Beta build, however, you need a valid key in order to use it.

Edit: Could be that you only need a valid key for the development builds. I was under this impression because those are the ones that I always download.

There was a period (about 6 months?) that ST3 was in "private" beta, and you indeed had to buy a license to use it.

For a while now it's in "open" beta, meaning everyone can download and use it.