You're missing the point here. helloworld.letsencrypt.org was used as the Test URL in the root inclusion ticket[1]. The certificate was renewed multiple times[2

You're missing the point here. helloworld.letsencrypt.org was used as the Test URL in the root inclusion ticket[1]. The certificate was renewed multiple times[2], but the expired certificate had to be restored at one point in order to satisfy some of the requirements of the root inclusion process. [1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1204656 https://bugzilla.mozilla.org/show_bug.cgi?id=1204656 [2]: https://crt.sh/?q=helloworld.letsencrypt.org https://crt.sh/?q=helloworld.letsencrypt.org