I'll admit the first place I tried to look up the phrase was on tvtropes. (It seemed like a natural following the manic pixie dream girl reference). When that didn't work I was amused that the only "article" google could really find was a checklist that seemed to be about par with the the "you might be a redneck" jokes. I am interested in reading the MLP article for the lulz but can't seem to find it.
EDIT: Still didn't find the original MLP reference but while looking I did stumble across some awesomely insane conversations on not just neurotypical privilege but other "abelisms" and "privilege." The following is either solid gold snark meant to start a flame war or scary insane world view but either way I laughed and figured I'd share.
"USING THE TERM “FUCK OFF” OR “FUCKER” OR “FUCK” IS ABLEIST.
SOME PEOPLE ARE INCAPABLE OF HAVING INTERCOURSE.
CHECK YOUR PRIVILEGE."
EDIT AGAIN: Which I just realized essentially boils down to "Check your fucking privilege."