This copypasta has been on internet before that movie but it’s cool that it’s made its way in there.

Not sure about its origins but here’s a blogpost from 2014 mentioning it: https://davidsatkinson.wordpress.com/2014/05/23/if-youre-reading-this-youve-been-in-coma-for-almost-20-years-now-were-trying-a-new-technique-we-dont-know-where-this-message-will-end-up-in-your-dream-but-we-ho/