After updating and re-booting, I am stuck on loading initial ramdisk ...
Pacman Log.
I am suspecting something went wrong with:

[2023-08-29T09:09:27-0400] [ALPM-SCRIPTLET] dracut-install: Failed to find module 'zfs'
[2023-08-29T09:09:27-0400] [ALPM-SCRIPTLET] dracut: FAILED:  /usr/lib/dracut/dracut-install -D /var/tmp/dracut.XG0qRp/initramfs --kerneldir /lib/modules/6.4.12-1/ -m zfs
[2023-08-29T09:09:27-0400] [ALPM-SCRIPTLET] dracut: installkernel failed in module zfs

Not enough info to give good advice, but is this install using a ZFS filesystem? If so, then complete unclear how you updated the kernel, without updating zfs-kmod. Things are actually packaged in such a way, that a major kernel update like this will block the update, if not also getting zfs build against that specific kernel version.
For full info, SysInfo is needed:
https://kaosx.us/docs/

Discussion split from Plasma 6 thread, since it has nothing to do with Plasma 6.
One reply to the split comment, ZFS is not default, so for default installs zfs-kmod is not needed.