If the signal does not change, then it is easy to know instantly what the signal looks like at any point along its waveform - even a light year away. It's a case of getting the message and the messenger confused. Phase and group velocities belong to the messenger, and signal velocity belongs to the message. If you are dealing strictly with a dynamical system containing real energy, then the signal velocity must be bounded by the properties of whatever is conducting the message. If a water wave only travels 30 miles per hour, then a signal propagated by water can only go as fast as the wave of water.
Signal velocity is bounded.
But you can't automatically say that signal velocity is therefore bounded under all conditions. Information is NOT the signal and has no energy. Relativity has nothing to say about non-energetic systems. Contrary to what Dr. Davies says, relativity is not broken nor does it get thrown away. Everyone is happy and there is joy in the physics community once more.