What Beta ? that's the first thought that crossed my mind also.. Is PP letting a select few test the beta?
It's all a joke. Look at the opening post of this thread. Adriaan placed a single tree and made out is was his new course done in Course Forge, just for laughs.
Dave then 'jokingly' thanked him for sending him the BETA of his 'course', with the one tree.
Obviously some folks have missed the joke and think that a BETA of Course Forge is available.