The only way one can say that the snipping of the foreskin unequiviocally equals a degradation of appearance is to have the stance that ANY change to somethings appearance is considered to be a degradation, in which case the above examples apply.
Elsewise, it does not. YOU may feel it degrades the appearance, while others do not. In that case it would be functionally factual for you to say that YOU believe it is Mutiliation, but it would be factually INCORRECT to state that categorically it is TECHNICALLY Mutilation because it does not adhere to the definition of it.
YOU may view it as mutilation all you want, many people view piercing ears as mutilation as well. However, it is factually incorrect to state it as an absolute FACT that it is mutilation because it is not a majorly held opinion that it degrades the appearance of said organ.