These victims were "likely asleep when they were attacked" according to the coroner. Not the kind of work that an impulsive, hastily-made decision from an ego-bruised dude from earlier that night would carry out (and so meticulously/efficiently at that). Indeed, this had to be calculated, quiet, and quick.
Far more likely a well-planned out attack from a sadistic, depraved mind that built up his fantasy over a period of months/years, couldn't resist the urge any longer, and executed his frenzy. Probably stalked them anonymously on SM via various channels and perhaps even kept up with their posted locations and/or used his own locators.
My opinion.