I think we "triple-dipped" a lot of archetypes: Princesses, knights, giant evil reptiles, cute animals etc.
Some character types are simple more common than the others.
I'm fine with having multiple characters who fulfill the same archetype, provided they do something different with their moveset. Peach and Zelda may both be princesses, but one focuses on traditional femininity while the other focuses on magic. Likewise, Bowser, K. Rool, and Ridley are all giant evil reptiles, but one is a bruiser based around raw strength, one is a goofball based around gadgets and cartoony movements, while one is a psychopath based around brutality and bait-and-switch fighting.
I'm not entirely sure how different Ryu would be from the other ninjas, would already specialize in fast yet weak attacks, a strong projectile game, and teleportation. I'm hoping if Ryu gets in, they put a heavy emphasis on his katana, with the other ninja qualities taking a backseat.