You’re being fooled by the way they’re posting the notices of new betas.
The notification of the release is the last post in the “Scrivener 3.0 Beta 8 (Download Links & Change List)” thread, and the release notes are the first post.
Weird, but you get used to it.
Beta 8, version 2.9.0.8, was released on August 1, 2018.