As far as I can tell all the talk of private or rented world’s stems from this post from 4 years ago, which references an even older post.
And although there are some forum members that have apparently had private conversations with devs and been told these are coming at some point, there has been no further public discussion, never mind confirmation, from the devs (if someone has a link to public confirmation, please post below!).
You will also see at the bottom of James post that it says the details are not final.
So really no-one know for sure the answers your questions, or even when/if it’s going to happen. Again, happy to be proven wrong about this if someone can link a recent (let’s say out of early access) link to confirmation.
Edit. Lol, just seen the updated post on forum, only from 3 years ago now, so getting more current!