No, they didn’t gender swap the original Slimer. They gave him an equally-gross love interest. “Slimer and girl-Slimer sitting in a tree. ACTUALLY they don’t have a corporeal form, so they can’t ‘sit’ per se.” Oh god, even my childish taunts are being interrupted by the pedantic fictional internet commenter in my head. Kill me. Then bust my ghost.
Anyway, Sony released two new TV spots for Paul Feig’s Ghostbusters which are definitely better-paced than the lambasted first trailer. At the very end of the second video below, we can see Slimer got himself a girlfriend. Or John Travolta wandered off the set of Hairspray. Could be either.