There is tons of discussion about how Beta testing works here.
Beta is just beta. When it’s bug free, it will go away and that curriculum will replace the current one at freecodecamp.org. All of your progress on freecodecamp.org will still be on your account when the new challenges get added. Beta is a test environment only, so nothing that you do on Beta will be copied over to your real account. (Account creation is even disabled on Beta to reduce confusion.)