If your app says a room type, that's the room you're in. There is physically no way for you to be assigned to a different room type than what your reservation shows. If your room type is changed at check-in, the reservation itself is changed in the central system, which is where the app pulls that information. It's also recorded in the reservation history. If ever in doubt, you can call Bonvoy or the Ambassador line and ask what room type they show you in. They can even see your room number.