[nickm12]

The article says that their focus should be on "new code, not rewriting existing components" and that Rust code is used in "new functionality and components".

Yes, one is named "keystore2" but you don't seem to actually know anything about it (nor do I). It seems doubtful to me that they would rewrite a perfectly working component in Rust just for fun. Most likely the original keystore, whatever language it was written in, was not meeting its requirements and needed to be replaced.