yeah, he totally did. EAs claiming otherwise are just incorrect.
remember that the original Roko's Basilisk post talked about the dilemma of being an "altruist", i.e. how to donate as much money as possible to MIRI (or SIAI as it was in 2010).
the terms were in extremely heavy use back then.
a bunch of the various Singer-inspired groups tried to work out a name for the whole thing, and they picked Yudkowsky's coinage.