A GSE watchdog has changed and adopted what it says is a new focus on public policy. But officials at Fannie Mae and Freddie Mac aren’t buying the claim of a metamorphosis on the part of critic FM Watch. “We’ve said all along that FM Watch is principally a group of Washington lobbyists, and now they are acknowledging that is true,” said Chuck Greener, a senior vice president for corporate communications at Fannie Mae,