I finally discovered why the rpi4 wifi device disappears in uptodate armtix.
It seems not to be a kernel issue
rfkill list show a device with
linux-firmware-whence-20230404.2e92a49f-1-any.pkg.tar.xz rfkill shows
linux-firmware-20230404.2e92a49f-1-any.pkg.tar.xz
$ rfkill list
0: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: no
however the wlan device disappears with
linux-firmware-whence-20230625.ee91452d-4-any.pkg.tar.xz
linux-firmware-20230625.ee91452d-4-any.pkg.tar.xz
this with a kernel based on the latest manjaro PKGBUILD
Linux pikat 6.4.7-1-armtix-rpi4 #1 SMP PREEMPT Wed Aug 2 15:01:20 BST 2023 aarch64 GNU/Linux
Edit: Interestingly manjaro also has packages linux-firmware 20230625.ee91452d-1 & linux-firmware-whence 20230625.ee91452d-1 and manjaro does have a wifi device.
The contents of the packages are different though eg
Only in manjaro/ware/usr/lib/firmware/3com: typhoon.bin
Only in armtix/ware/usr/lib/firmware/3com: typhoon.bin.zst
Only in manjaro/ware/usr/lib/firmware/acenic: tg1.bin
Only in armtix/ware/usr/lib/firmware/acenic: tg1.bin.zst
......