So, is that a dagger? (In the new concept art.)

[Ramsey]

This concept art clearly shows our players in water! So we must be able to swim and tread water in 2.2!!

No it does not, it clearly shows players sliding down the surface of the boat, which is being hit by a crashing wave. And yes, this does actually happen in the Leviathan fight.

People saying "it's simply artistic liberty" obviously haven't been paying attention to how careful they are with their promotional art.