I think the reason for few recent threads is Pause shut down so much, and summer is coming now, so group cruises are picking up.
The last time I remember regular threads about big groups was before Covid. The cruise I referenced that my friends went on was (I believe) July 2018. It was the previous season that someone posted about a very large group booking over half the ship and getting dining together, so they could have a speaker, and the showroom reserved for their productions. Non-attendees got to dine elsewhere and one show.
Way back in 2013 I was on Veendam to Antarctica and a large (~300) LDS travel group had booked with their own speakers. They did have the Showroom booked privately a couple times a day, but I saw no impact with that. We still had the full complement of Antarctica programs. (The only impact on me was their speaker was given leadership of the “interdenominational service” on Sunday, so I attended mass with my catholic Christian brothers and sisters.)