A note before answering your question: The current RHEL 9 beta is not a 9.0 beta, it’s a 9.-1, basically, and won’t be what will be GA in 6 months time. We have no plans of building that beta in particular. We will build a 9.0 beta when that’s ready.
To answer your question though, we are not building 9 stuff just yet. We are currently finishing up some pieces of our new build system to present to the community for general use, SIG work, and open development. That new build system will be used to build Rocky 9. We may be ambitious (and maybe a bit idealistic) that we can build out Rocky 9 and have our own release within days of upstream release, but we want to try to see if we can. (We are volunteers after all, and we have 6 months of time before 9.0 releases)
Either way, we want to do this with quality in mind. And that’s why we want the build system ready to go first and available to the public before anything else. We hope to have information in the coming days!