Though it certainly won't be surprising if throat capacity eventually becomes one of the many goofy things that gets tracked and measured.
Snakes are able to extend their glottis out the side of their mouth while they eat, which allows for respiration while they consume large prey items.
I'd actually planned a snake jaw TF for a project already just for deepthroat scenes, but this previously-unknown tidbit just solved like three problems at once. Soon, maybe.