And when it doesn't, borosilicate too can shatter due to thermal shock. Hence, "Don't forget that borosilicate glass also cracks with thermal shock".

Here's the Consumer Reports article on the topic back from 2013, at https://web.archive.org/web/20130430032310/http://www.consum...

"""We baked at least five samples of each brand in a 450-degree oven. All of the U.S. Pyrex and Anchor dishes shattered when placed on the wet countertop. None of the European dishes made of borosilicate broke, except one practice-run Arcuisine Elegance dish that had been through two baking cycles in our lab. At 400 degrees, we tested two samples each of the U.S. brands against two samples of Arcuisine. All of the American-brand dishes broke but the European brand did not.

When the oven was turned up to 500 degrees, all three of the European Pyrex dishes broke and two of the three Arcuisine dishes broke. We also tested a decades-old Pyrex dish in like-new condition given to us by a staff member's mother. Made by Corning of borosilicate glass, it didn't break, even at 500 degrees"""

The European Pyrex dishes were made of borosilicate glass.

To be very clear, these temperatures are extremely high, and "the test was contrary to instructions on the back of the label." The goal of the test was to see what the safety margin might be for cookware which might get scratched or damaged over time.

> Tempered soda lime glass may well have an advantage there (but any object & its material has its limits of course).

The sources I pointed to say it does have the advantage, and that advantage outweighs the thermal shock advantage.

Pyrex cookware can break in the microwave. So can glass cookware from other brands.

These incidents are RARE.

Your original claim is that they are "likely." This is wrong. Your new claim is that it "breaks in the microwave". Leaving out a qualifier implies it is inevitable and common. That interpretation is clearly wrong given the hundreds of millions if not billions of such glassware in use.

"Pyrex" is a brand name. You need to be specific. Do you mean Pyrex soda lime glass, Pyrex borosilicate glass, or both?

Why do you not care about non-Pyrex brand glassware?

> The platen glass is doped with a microwave absorbance metal to provide some protection to the magnetron

I am not able to verify this claim. As best I can tell, I was wrong - borosilicate glass is most often used, not lime soda. See https://patents.google.com/patent/JP2013063861A/en ("As the glass used for the turntable, borosilicate glass having a low thermal expansion coefficient and excellent thermal shock resistance is used.")

While boron is a metalloid (not a metal), it is not chosen for microwave absorbance reasons.

I do not believe your claim is true because "microwave absorbance metal" means the glass will heat up faster than otherwise, which is not what you want.