We were on the Sun about 4 years ago and Princess provided many meetings----in the disco and the deck above the main pool. Bartenders were provided in both places.
To be sure that there are Friends of Dorthy meetings, just write a note to the Cruise Director making a request and drop it off at the Pursers desk. Include your name and cabin number and ask the CD to post the meeting times in the Princess Patter daily newsletter. That's what we will do when we board the Regal Princess on Memorial day (see our Post on this page). Princess has never refused our requests, and we've been on several of their ships.
Hope this helps.