That is a setup guide for hardware key and passkey auth. It is not a hardening guide, and does nothing to mitigate these LPE vulns.

This is said in the article:

To mitigate the risk posed by these flaws, it’s essential to apply patches provided by the Linux distribution vendors. As temporary workarounds, users can modify the Polkit rule for “org.freedesktop.udisks2.modify-device” to require administrator authentication (“auth_admin”).