We were onboard QV for [I think] Harry's wedding. Whatever the Royal occasion, it was screened in the theatre and the Grills lounge and we had a Gala dinner with a specially produced souvenir menu [which I threw away and thus can't totally be 100% sure of the occasion] and a complimentary glass of something bubbly with dinner.
Also, docking in the Seychelles and again, I can't remember the occasion but there was a beautiful faux cake celebrating the Queen on the quayside in 'our' honour and again, a bit of a do onboard so quite frankly, I can't imaging a once, for many, in a lifetime Royal occasion, namely the coronation of a British monarch going uncelebrated in quite a big, but Cunard'ishly dignified, way.