https://wccftech.com/fallout-76-beta-includes-full-game/

Have you signed up for the Fallout 76 beta yet? If you’re at all interested in the game, you should probably get on that, as it turns out the beta gives you access to the full Fallout 76 experience. That’s right, you can play the entire game and all progress will be carried over when the game launches in November. In other words, Bethesda is essentially doing an early access launch, rather than a traditional beta.

This information was revealed on the Fallout 76 beta FAQ page, which was recently updated. Here’s the exactly wording of the question/answer: