From Comics Alliance:

A DC Comics spokesperson told CA, “As acknowledged by the creators involved, the editorial differences with the writers of Batwoman had nothing to do with the sexual orientation of the character.”

This reinforces my suspicion that Rob is on the wrong track with his article on the subject. The reason behind the editorial edict is probably a line-wide version of what Marvel did with Spider-Man in One More Day: Nobody gets married, because married characters are somehow less interesting. That's why Superman and Lois Lane aren't even dating anymore.