That article sounds like QM2 before covid. I have not been on her since then. But I was on the QE in July. Zero dance hosts. Music in QR is not my favorite. The most crowded night of dancing was the Big Band Night. I am not sure why Cunard has gone completely modern in their ballrooms. I am not really wanting to dance to "Don't ya wish your girlfriend was hot like me"? in the ballroom. Yes I am younger than many of the "average" age of Cunard pax but I sail Cunard because we love hearing big band and Sinatra and the like.
Not sure why they cannot mix a few modern songs along with a few standards in the evenings i the ballroom if they are trying to trend in that direction. From my observations, it was not a popular change. I think people want a mix but who knows. The most popular night was the night we heard all the standards. The article linked by the OP was a complete fallacy.
As for International dance couple - we had one and they performed in the queens room, gave all the lessons, and danced in the Yacht Club with passengers.