Happened on our last cruise. They moved our adjoining rooms to non-adjoining rooms. Didn't notice until I read fine print in some email they had sent us. I didn't care where we moved to as long as rooms were adjoining. 4-5 hours of multiple people calling NCL, we were able to get adjoining rooms. We had to pay a little more than original booking, but were just happy to have adjoining rooms. Subsequent to cruise, NCL made a generous future cruise offer.
Adjoining rooms vs. non adjoining rooms is a huge deal for our family.