I'm not sure how their PR dept spun it but borosilicate glass is incredibly resistant to sudden changes in temperature as well as having better chemical and acid resistance making it ideal for chemistry lab work, presumably some news stories broke about 'amateur chemists' using Pyrex cookware for a different type of cooking. It's not like borosilicate is a controlled material though, the reason for the switch is likely that soda lime glass is significantly cheaper to produce, they did suggest that their soda lime glass was more mechanically durable but then again borosilicate glass is also known for being mechanically durable.