The linux-firmware package 20220119.0c6a7b3-2 implements kernel
firmware compression. Linux kernel from 5.3 on support loading
from xz compressed firmware.
CONFIG_FW_LOADER_COMPRESS kernel option must be enabled. All official Arch Linux kernel support this for a long time. 
The linux-firmware package has been split into smaller packages to
further reduce required disk space. Some big firmware files of
rarely used hardware have been split into separate packages.
This affects firmware for Mellanox Spectrum switches, Marvell devices,
Qualcomm SoCs, Cavium LiquidIO server adapters, QLogic devices,
Broadcom NetXtreme II 10Gb ethernet adapters.
Make sure to install additional firmware packages if needed. 
 FS#72559 +
If you see software failing with:
error while loading shared libraries: libicui18n.so.69: cannot open shared object file: No such file or directory
This means that the software (or a library) has not been rebuilt against newest icu (70).
As a temporary workaround you can install the old libs with:
The same applies for icu68 and icu67.
If you have software that does this, please also raise a bug or bother the devs on irc so that in the future we can fix it properly.
If using zstd 1.5.1 you end up with an unbootable system (dbus doesn't start, all systemd subservices fail to start).
This is fixed in zstd-1.5.1-2.1.
Due to a non-working signing of libraries nss-3.73 has been built without signed shared libraries, causing firefox
to simply crash.
This is fixed in nss-3.74-1.1 now.