but if someone were to say or even imply that any halachos or mesorah or minhagim are wrong or bad or mistaken or ought to be modified, they are violating numerous issurim.
To say a Halacha , Mesorah or Minhag NEVER changes is just factually incorrect
Pruzbal is just the most obvious example, but there are others, Like most (not all- some still do this) do no put ashes on their forehead at a wedding