It's more of a gut feeling than anything else. I don't know what the normalization rules are, but I think we mostly notice the normalizer when it mangles something [1], and not when it's just quietly humming along. Someone with more spare time could probably figure out a dataset of original to normalized titles and measure that.

[1]: Example from the frontpage right now: "How Big Are Factorials?" probably got normalized to "Big Are Factorials?" originally, based off other previous manglings I have seen previously.

Neutering Popular Science clickbait titles like “This Koala has a Secret Trick!”