Do files in /dev/shm (@SUMMONENVFILE) get cleaned up?

Do files in /dev/shm get cleaned up somehow by OS or by Summon? I am just curious, because I thought one of the main ideas behind this project was to avoid having plain-text representations of our secrets laying around on the OS. But if we're just putting them in /dev/shm, aren't we essentially just moving the plain-text around, not eliminating it?

(disclaimer that I'm sort of a noob, and this may be a silly question)