new material you theming support for app icons
Not integrated into GrapheneOS yet.
any material you customization settings (under wallpaper and style)
Also not integrated into GrapheneOS yet.
qr-code tile appears but is gray and says "unavailable".
More works needs to be done to hook that tile up to GrapheneOS's camera app.
Are those features to be added with stable?
No. Stable is already out. Those features will be added eventually, but they weren't put in the initial Android 13 release because the priority was getting the full August security update and the rest of Android 13 out as soon as possible.