It is, which is why you want to be conservative. If the duplicated code is obviously supposed to be identical, then predicting the future should be trivial. If

It is, which is why you want to be conservative. If the duplicated code is obviously supposed to be identical, then predicting the future should be trivial. If it's not obvious, then it's a question of "can I conceive of a reason why I'd want to update one and not the others?". And if the answer is unclear, wait a while and see if anything comes up.