I do not play games on my MBP and the few times that I have had runaway applications, I have immediately restarted my machine so it has not been exposed to high temperature for any prolonged period . I have seen on this forum users who have reported shutdowns due to heat and have restarted the Mbps. I also have seen very experienced participants indicate that indeed there are shutdown provisions for heat in the MBP.
What I suggest you might do is call Apple support back and pose the same question again. They have centers through out the country and you are bound to talk to a different representive. Don't accept an 'I think' answer. This is clearly a yes or no situation. If you cannot get a definitive answer, insist on talking to someone who knows for certain.
Though I am of the opinion that the MBP will shut down, I would be most interested to know if I am wrong.
I just called Apple Care my self and the representative asked a senior advisor about the question, if the MBP will shut down due to high temperatures. He said that there is a 'hardware kill switch' inside that will shut the unit down if it reach temperatures that will damage the MBP.
I was not left with a "wishy washy it's a maybe" impression how the answer was presented to me. I still would like to hear what answer that you might get.