Apple just shipped a fourth beta of macOS Golden Gate 27.2, one week after the third.
Registered developers can grab it now through System Settings, under General, then Software Update, by opting into the beta program. The build expands Siri's AI features to additional languages and adds new sliders for brightness and volume. Apple has not detailed what changed since beta 3. A general release is expected toward the end of October.
Weekly beta cadences like this usually mean a release is close, and bug fixes rather than features are the priority at this stage. The real story is Siri's slow language rollout, which says more about the difficulty of Apple's AI retooling than any single beta does.
Four betas in a month for what sounds like a minor point release is a lot of iteration for brightness sliders. Make of that what you will.