I think the proposal was to thread-restrict variables, not objects. (Or more precisely, any variable is either restricted to a thread or guarded by a lock.) So

I think the proposal was to thread-restrict variables, not objects. (Or more precisely, any variable is either restricted to a thread or guarded by a lock.) So it wouldn't actually stop you from accessing any object you want, as long as you can reach it from something in scope. But it also might not be a very useful safety guarantee.