The last time the bones were examined was the 1930's and then, so I read, they were replaced higgledy piggledy back in urns, to be forgotten about. I disagree that they couldn't be the Princes. Yes, there were many people living at the Tower and yet those boys disappeared after a certain date as quickly and quietly as if they had never been, at a time when Richard and his minions were in full charge of the place where they were kept in captivity. The stairs were in a very private part of the Tower used by King Richard for private prayers, and led to his Chapel.
I think there's a good chance they are the remains of Edward V and Richard York, (when they were found in the 17th century there were reportedly scraps of velvet found with them, a material that was unknown to the Romans, plus what are the chances of these particular Roman bones being of two children of exactly the same age range as the missing boys) but we shall never know if it's left to the Abbey authorities.