If theyre gonna stick to the historical themes of the games then im sure they will use another animal species for all of the new ships they introduce.
I reckon theyll keep all of the old catalogue of ships somewhere within the game and simply update the models to look awesome with all the new graphical capabilities these days. I also reckon some of the cooler old ships will be hard to obtain within the game, maybe hide the Cobra MkIII at the end of some tough mission maybe?
And any new line of ships will probably get named after another animal species, maybe something as simple as seafish?
Marlin, Stingray, Bass, Conger, Lamprey, Skate, Tope, Pike
So theyve already done Snakes, Big cats and Birds of prey so whats left to use?