I cannot with Certainty state anything about microprocessors (or almost anything else). And while I agree with your insistence that data sheet limits not be violated in designs, I must also point out that data sheets are full of errors and assumptions.

With Authority, I can state that the same laws of physics apply to everyone, and that there is very little difference in the fabrication technologies used by everyone to make their chips.

As so with Authority, I'll say that an hour of 100C operation will have negligible effect on a CMOS device lifetime.