As an operator, shouldn't you worry if something battle-tested, that implements extremely critical functions that are tricky to implement correctly, is replaced

As an operator, shouldn't you worry if something battle-tested, that implements extremely critical functions that are tricky to implement correctly, is replaced with something that is unproven? As someone who enjoys sleeping at night, I wouldn't poke something like that with a stick before it has matured for a few years, and before many brave (?) operators have smoothed out most rough edges by landing on them repeatedly with their faces.