Don't play stupid.  You know damn well bitcoin is not fungible nor money by definition, and that an "evolving protocol" is also never going to be fungible even if you do mix the outputs.  I bet you've also made conflicting statements before about segwit claiming that it's really a fork or something even though the wallets are technically compatible, thus fit within your definition of equivalence in fungibility.  

If you assume each transaction type has completely different surface attacks vectors like attempting to turn segwit transactions into anyone can spend transactions or what have you, how could they possibly be fungible?  This is the never ending cycle of a so called "evolving protocol".  Just about nothing in it is fungible.