yeah it's the same issue. plymouth renamed it's modules that's why it happened.
WARNING: The 'plymouth-encrypt' and 'sd-plymouth' hooks are no longer exist in the package. You should replace them with 'encrypt' and 'plymouth' hooks in your 'mkinitcpio.conf'. The 'lxdm-plymouth.service', 'lightdm-plymouth.service' and 'sddm-plymouth.service' systemd service files are no longer exist in the package. You should enable 'lxdm.service', 'lightdm.service' or 'sddm.service' instead.
This is the warning that plymouth gave follow it to fix your system.