Don't know for sure - but port times are controlled by the dock master in the port and can be a political sot of thing. Also weather forecasts and tides can play a role in determining the times. Portmapper doesn't show a lot of cruise line traffic so I don't think other ships are impacting the timing. BTW - the board for this cruise is https://boards.cruisecritic.com/topic/2879268-vision-of-the-seas-may-20-2023-bermuda/?do=findComment&comment=63907075
I started this not knowing that someone else had created a prior board.