where did you get the impression they are not rewriting code in rust? because the author cited some other blog post saying they should focus on new code and not rewriting it? How does that translate to "The whole point is that they are not rewriting code," ???
Obviously they're going to be rewriting whatever they see fit. If YOU actually read the article you would have seen they have "keystore2" listed as new rust code. I WONDER what was keystore1 implemented in? Nice try, but no cookie.