Chapter 1 says:
While Apple’s iOS Simulator is now capable of receiving push notifications during development, it is still not capable of receiving remote notifications. If you don’t have a physical device, such as an iPhone or iPad, you won’t be able to work through Chapter 6, “Server-Side Pushes”.
As of Xcode 16, the simulator can register for push notifications and even receive (and display) them. The simulator token differs from the device token in format - it is longer. So you can tell at a glance whether the token belongs to the real device or the simulator.
But the main point is that the simulator is now able to receive at least alert pushes and maybe other types of pushes as well.