Protocol/code is law. Having UTXOs with different history has no implications of how it is spent on the protocol. Thats what matters. You can put all the goofy identifiers like “omg this was owned by this KYCd person”! But doesn’t change how it is spent or how the protocol receives it. When everyone is dead in 200 years and they find kyc bitcoin do you think they are just going to toss it aside and say “that’s not bitcoin it was KYC’d 200 years ago, toss it in the “fungibility grave yard”. Nah they are going to spend that shit like any other coin. A UTXO has a unique identifier, yes, I don’t see how this makes it any less valuable or interchangable than another UTXO with the same amount that is nonKyc. Increase your time preference and see how nonsensical this is.