Don Pacifico
The dropped goalkeeper was on the bench in all 5 league games, so it was clear rotation by Brighton.
Personally, I agree with the consensus that Raya is number 1 and there won't be the kind of rotation that Arteta is alluding to. Ramsdale will likely play in the cups and that's it.
But this idea that you can't rotate goalkeepers is a limiting belief like every other, up until you can do it. Brighton are doing it as we speak.