Scrivener 3 for Windows but when?

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.