You're using a logical fallacy then. You're specifically defining the word so that it isn't what the opposition says. Like if someone defined the truth to be whatever proves their point-- logic doesn't work that way.
Codex creep is, simply, the fact that codices produced later are stronger in some way or other than those produced earlier. The means for them to become stronger is irrelevant, however. Regardless of how you feel about it, the fourth and third edition codices are still used and the fifth edition codices must still therefor be judged against them regardless of the age of the codices and what edition they were designed for.