Yes it should. Water stains indicate damage to drywall because the water has penetrated all the way through to create the stain on the ceiling and no amount of painting will make it go away. Since you say the contractors "took forever" to remove the insulation, my bet is that there might be some mold growth where it was the wettest for the longest amount of time since, generally speaking, untreated water problems can lead to mold growth in as little as 3 days. Of course there are other environmental factors involved and, without a visual inspection, I can't tell you if this has happened. That being said, my recommendation is to take out the wet drywall and see what is there. If what is above the ceiling is dry, if nothing else, you will be removing the stains once and for all.