Shame I hadn't seen that thread. He's right that most of the rust projects "replacing" standard Unix utils are not feature equivalent and differ in intent, but that doesn't mean there aren't other efforts to do exactly what he is asking.
Eg here's tac (admittedly not cat, but hey, ./goo | tac | tac) published a few months before his email: https://github.com/neosmart/tac
Eg here's tac (admittedly not cat, but hey, ./goo | tac | tac) published a few months before his email: https://github.com/neosmart/tac