[lvh]

They computed, verified and measured wear and tear (lifespan in Gy) as a function of temperature. The paper, which I linked, includes the full plot. They had to pick _some number_ (temp or years) in order to communicate it as one data point. There's nothing special about 462K -- it's what happens when you pick the age of the Universe as how long you want it to last form now. Pick a billion years, or 10 billion, and you get a different temp.

Given that they had a hypothesis, designed an experiment and validated the result, it seems a bit much to say it "flys[sic] in the face of the foundations of science".

[AstralStorm]

And finally the disc will never reach that, because it will not physically survive (or it's surroundings) to reach that time.

Not on Earth, not in space, when real considerations like impact resistance are in.