Woah, that fixed it!
I disabled the asus-nb-wmi module with
$ sudo echo "blacklist asus-nb-wmi" >> /etc/modprobe.d/blacklist.conf
$ sudo modprobe -r asus-nb-wmi
and now the WiFi shows as enabled both in the GUI and unblocked via rfkill
rfkill list wifi
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
Thank you Jeremy31!