To me, gender bending would be a step toward the characterization skills needed for original characters. I’d suspect that an older abbreviation “OOC” (out-of-character or out-of-canon) would definitely fit this scenario, as gender bending is a specific modification of that canon character, but it’s still based on a canon character. Some canon characters are...like a name only, so lots of fanfic writers take one of those and fill in the details. Obviously, if I hit the random name generator, create all new details, and insert that, it’s an original character (and I’ve done that repeatedly with my fanfic where I need characters).