Welcome to the forum!
No, these are still in a pre-release branch. They may make it into a release version of Reaper, maybe soon, maybe not-so-soon, maybe never. This is why it is generally asked to keep any discussion of pre-release thingies within the pre-release forum; its a public forum, its just as visible, but its a useful conceptual barrier to head off the feeling of uncertainty you might be having right now
Imagine if you made a whole theme that relied on functionality that never made it to a release version. You'd be furious, right? That's why its best not to cross the streams, so to speak.