It was a joke, based on the previous treatment of the characters ,
Dan Didio is homophobic. To amuse himself, he lets Chuck Dixon, a noted homophobe, write a Grifter/Midnighter series. Following THAT, he puts Mike Miller on the Authority, despite having fired him years ago for making grossly offensive homophobic comments. THEN, reboots the characters to get rid of their pesky, Jesus-baiting gay marriage. I've read four issues and NOTHING indicates that they're a gay couple.
Of course, the series is so bad they barely resemble Apollo and Midnighter to begin with, but, whatever. I just thought Cornell, who's married to a friggin female Vicar....I've had drinks with him - I just thought he'd be better than this.