Maybe this will be true legally (we wont really know until it is tested in court), but I think there's a huge difference in practice.

Siri Recap is an electronic record of a conversation that includes timestamps. Imagine for example that during a scheduled meeting with my boss, he threatens to fire me for not doing something illegal. I now have strong evidence that this was said (even if it cant be officially attributed to him) during the time I was in a meeting with him. Not saying this will hold up in court, but it certainly is more damning that having written notes (not to mention the fact that my boss probably wouldn't say this when I am taking written notes).