First, (maximally) entangled states always act exactly like a perfectly random state, until you compare the two. There are a lot of experiments that can be called “delayed choice” experiments (here’s a good one! What does Bob see if Alice does nothing? In order to ask “what does Alice see?”, you have to consider which “version”. From this Alice’s perspective, the state of Bob’s particle has undergone “wave function collapse” into the top state.