I suppose it's possible, but I can't figure out how all three would have done that.Could they all have broken the toe in the same place and it healed back that way?
I can't really remember if they had it right out of the shell or not.
Were there other chicks in the incubator and brooder with them? If so, and if the other chicks did not have toes like this, it is even more unlikely that these three would get injured in exactly the same way but none of the others did.