No idea, I would hope that if it was supported it still is. Crossfire at it's best has been a mixed bag of results. Many (probably most) find it not worth it. For every game that works with it well, there are way many more that the dual cards either, doesn't work or it creates an issue that doesn't exist with one card. Hopefully down the line with DX12 and Multi-GPU this gets better, but I wouldn't hold my breath there either.
I would highly recommend you save a buy a single card solution capable of running at the resolution you want.
