I think that was there before this most recent update. But I used the rocks to clip out of the map and took a stroll over there to be sure. Stood where the entities were and nothing happened.
One thing I really liked about this update was how replaying the game while vigilantly searching for eastereggs really helped me notice some of things I didn't before.
I also can't help but point out that even some of the people in this thread have done the same thing, mistaking these oddities as 'new', much as I did.
Awesome way to get us to appreciate the game once again