I am attempting to bulk prep some frozen convenience food and have determined that a standard Pyrex glass container would be ideal for freezing (non-liquid) meals (think burritos or tacos), but I want to ensure it is safe to induce a huge temperature swing, or if there is a better way to do this.
It not huge, it's just the difference from freezer to room temperature you are worrying about
E.g. -20°C to 20°C, is A 40°C shift. The shift was going to be 20°C to 100+°C anyway. There is no physical reasons why this would be anymore stressful
From room temperature you are raising it 80°C, from frozen you are raising it 120°C. Not a problem in the normal temperature range for glass
The freezing temperature of water (most common item in food) has no relation to the freezing temperature of glass etc
Pyrex and other glasses can be damaged if one part of them is instantly heated or cooled by a 100°C or so
Pyrex used to be made with BoroSilicate glass. Now some Pyrex is made with SodaLime glass, which isn't so tolerant of rapid temperature changes. So you need to follow the instructions for the dishes you have.
If in doubt don't heat Pyrex straight from the freezer. Rather eg transfer contents to another such dish already at room temperature for heating (if you can't wait for it to defrost naturally). http://www.consumerreports.org/cro/magazine-archive/2011/january/home-garden/glass-cookware/glass-cookware/index.htm