I belive that restriction was lifted quite a while ago, like in 2010 or something. It didn't last long as game engines required the use of scripting languages for game logic, among other things. Apple simply had to cave in.
Excuse my ignorance, but what about the new situation that all apps MUST use ARC. Does that interfere with lets say embedded Lisps in Apps etc...
You don't have to use ARC. You can reference count manually if you like. What you can't do is use the old garbage collection (which was only ever available on OS X).
And in fact you _can_ still use the old garbage collection if you really want to; you just won't be able to submit new apps to the OS X app store.
Apple no longer allow use of Objective C garbage collection on the MacOS App Store (it was never supported on iOS). This doesn't effect third-party garbage collection and there's no requirement for third-party languages to use ARC (it wouldn't be practical for most of them, anyway, though there is an AOT-compiled Ruby that uses it).