I cannot speak to what they are doing now on MDAS cruises but I can to my past experience in 2019. There will still princess things onboard. MDAS is just that.. a single day at sea. While there is a big Marvel background to post near in the atrium the entire cruise, they really only go full Marvel for the one day.
As someone else already posted, it seems there are no Pirate's nights on the upcoming MDAS cruises this year.