What will be in macOS “Mammoth”
What will be in MacOS 13?
Anyone who knows can't tell you.
Further, just because something is planned doesn't mean the feature makes it in the final; also, some things make it in that even Apple engineers not directly working on it know about.
Source: am former Apple engineer.
You can tell us what you’d like to see by filing a feature request on Feedback Assistant! 😁