More taxing or more stress in and of itself is meaningless without context.
As someone who has worked in product development, I can tell you that good design Always leaves a buffer to handle loads higher than is ever put on it. This is standard industry practice that I'm not going to cite for you and Tesla has many brilliant engineer's who I'm sure follow this mantra. We also have plenty of sources to show the motors in the P are the same as the AWD, no? So in the scenario that all the AWD's are suddenly at P level power, it wouldn't make sense that there is a higher likelihood of warranty claims - atleast in relation to the motor itself. Now if there are other factors outside of that motor on AWD vs P, or Tesla just has poor engineering and low tolerances then obviously it changes the suggested outcome of this scenario.