We were on the maiden crossing in April of last year and on the second to the last day out, there was indeed a FOD posting in the daily newsletter. It was held in the Commodore Club which is a great venue at one in the afternoon. We did not attend but were pleased that a FOD get together was arranged by the management. So, to answer your question, Cunard does hold FOD socials. Have a great cruise, the ship is fantastic!
My partner and I were on QM2 in July last year and there were two or three FOD meetings, although we didn't attend any. We've always found Cunard very gay friendly and on all the cruises we've been on with them, there have always lots of gay couple. Coincidence or not, we don't know, but our cabin last summer was made up as a king-size bed.
As Mark says, the FOD gatherings were held in the Commodore Club - I think that's the best venue on the ship, especially if you're sailing inshore as we were - the Norwegian fjords and the Elbe and Maas Rivers.