The relationship between Riker and Troi came out of nowhere. It would have been nice and would have made for greater drama to build up to the wedding during the movie.
It really didn't though. By the end of Insurrection they were a couple again. We went through seven years and two films of the will they/won't they get back together backstory and I guess all it took was the Fountain of Youth planet to push them over the edge and into a bathtub once and for all.