Derek Jeter gets a sex change. The Miami Marlins are hosting Free Pitbull Night and the San Diego Padres would like to encourage all handicapped fans to stay home. Sounds like an all sports version of SNL’s Weekend Update. There, it would be funny. But on the official Major League Baseball Facebook Pages, not so much. Yesterday, these kinds of posts appeared on a half a dozen official MLB Pages and fans assumed it was the work of a hacker with a grudge against baseball. Turns out the posts were loaded by an authorized Page admin who went “rogue.”  The person in question wrote the posts as a joke and says they were never meant to appear in public. He also told Deadspin that the ones that went live weren’t even the “best” of the…