By derby, John Henry's wife is referring to the Merseyside derby, a Liverpool soccer game that is apparently a big deal.
It's fine that John Henry owns Liverpool. Wealthy people make investments in a lot of different things and owning a soccer team does not in any way preclude the Red Sox from winning the World Series. He owned the soccer team when the Red Sox were in first place all those weeks, too.
But this sort of Tweet, coming a day after Terry Francona was let go as manager is tone deaf. Those associated with the team could at least pretend they're disappointed in what happened this season.
Henry himself has yet to speak about Francona or the collapse of his team.