The short version is that they're different kinds of reproducibility.
The reproducibility that this post is about is for auditability ("verify that the binary originated from the claimed source"), whereas the reproducibility in Nix is for reliability ("ensure that the same package either fails or succeeds on every system in the exact same way, regardless of what the environment looks like").
Both are nice to have, but they are only tangentially related.
The reproducibility that this post is about is for auditability ("verify that the binary originated from the claimed source"), whereas the reproducibility in Nix is for reliability ("ensure that the same package either fails or succeeds on every system in the exact same way, regardless of what the environment looks like").
Both are nice to have, but they are only tangentially related.