Here's your risk:
Lets assume (theoretically) that you do indeed tie together the neutral and ground at the cooktop, connecting them both to the EGC. Now just for fun, lets sever that EGC. Customer turns on stove and causes some kind of 120 v load. Neutral and ground have been bonded at connection point. Customer touches stove. What happens? They complete the circuit. Dead customer. Your license goes bye-bye.
This doesn't happen when you keep them separated all the way back. A severed neutral is just a severed neutral. (And yes, this same risk exists in pre-1996 3-wire stoves and dryers, but that is completely besides the point).
I'm not even an electrician (which is why I barely pipe up here unless I know i'm right) but this is so blatantly obvious to me...
