I've used my Pyrex cookware many times in the microwave to cook food and heat up food and yes the Pyrex does get hot to the touch in the microwave which is okay.
Other microwave safe glass dishes are also able to get hot in the microwave due to the heating of the food and the heat created in the microwave.
Pyrex even when it gets hot is microwave safe but just don't immediately put the hot Pyrex cookware into the freezer, refrigerator or into cold water because the shock from hot to cold of the Pyrex could cause it to shatter.
I've never had any issues though with cooking food or heating food in my Pyrex cookware in my microwave and have done so for years.
Even regular glass bowls, plates etc will get hot to the touch when microwaved so Pyrex will too.