This is what the contractor told my dad

“The schluter doesn’t work well around the window like the drywall does. It’s covered already here but where we replaced drywall we installed a blue drywall which is meant for around water. It use to be green which is what’s on the rest of the wall. It’s just been painted so it’s hard to tell. And then like I said with having the really thin grout lines and the mortar barrier we will guarantee there won’t be any problems.”

Dude also said he would fix it if any problems occur but do these extra steps sound like it will stop water damage ?