Although this is true to an extent, there is no way to absolutely make sure it doesn't happen without leaving a massive amount of performance on the table. There is a reason why TDP is calculated on average load these days and not on absolutely worse case load for pretty much every chip. You can't squeeze out performance during the average use case if you are worried about the worse case scenario. The difference between a typical game and Furmark is very significant to the point where it is recommended to not even RUN Furmark cause it might damage your GPU.I don't understand this quote ... The APU should have a max rated power draw, and the cooler should be designed to handle that max power at a particular ambient temp and assuming adequate space has been given for airflow. So as long as your environment is within those ranges, if the APU drew it's max power, which should be an unrealistic number, the console should not overheat. If my console ever overheated in an ideal environment I'd be pissed. "It's the software's fault," would not be an acceptable answer.
It is not unrealistic to have some parts of code that will run outside the TDP of any hardware and devs should absolutely make sure their code isn't doing this for long periods.