Yes, my bad. I did speed read the thread and missed points.
I’m not aware of a method to suppress selectively only the error messages.
For thunderbolt check if the hardware is present
lspci -nn | grep -i thunderbolt
lspci | grep -iE “thunderbolt|usb4”
the kernel modules
lsmod | grep thunderbolt
kernel sysfs
ls /sys/bus/thunderbolt/devices
retry
boltctl list - a
I don’t think so, this website also don’t show Thunderbolt feature for my Mainboard:
https://geizhals.de/gigabyte-x870e-aorus-elite-wifi7-x870e-a-elite-wifi7-a3286589.html
[koboldx@koboldx-x870e ~]$ lspci -nn | grep -i thunderbolt
1c:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM4242 USB 4 / Thunderbolt 3 Host Router [1b21:2425] (rev 01)
[koboldx@koboldx-x870e ~]$ lspci | grep -iE “thunderbolt|usb4”
bash: usb4”: command not found
[koboldx@koboldx-x870e ~]$ lsmod | grep thunderbolt
thunderbolt 602112 1 typec
[koboldx@koboldx-x870e ~]$ ls /sys/bus/thunderbolt/devices
[koboldx@koboldx-x870e ~]$ boltctl list - a
Ohh woow there is Thunderbolt in the logs.
I have to add the info that i have manually disabled USB 4.0 Ports in Bios. (Unsure if this both features twined with each other).
I HATE ASMEDIA. Yes, thunderbolt and USB can come on a type c. They are different things but can use the same port. In fact I seem to have read typec somewhere in the snippet you posted.
Do I remember well : you turned this off in the bios?
Yeah i disabled USB 4.0, because it had a special cooling solution and a additional chipset only for the new USB 4.0 Ports… i wanted to reduce heat and energy, my mainboard gets pretty hot, even in idle PCH is between 58-61° on a fresh boot (related to HWinfo which i use for temp checks under Win10)
Is there a way to finally disable the service under Linux?
Beyond blacklisting thunderbolt I don’t know other methos
I don’t mind, how blacklisting works? I never blacklisted anything under Linux.
Is there something important to know when i blacklist thunderbolt… for example maintenance related maybe? Or anything else?
Well usb4 is the amd equivalent of thunderbolt so you have already disabled it. I had the suspicion the logs call usb4 thunderbolt and disabling it should remove the message. I was wrong but on the other hand now we now that error is also kind of fake if it is there for something non-existent or disabled.
Blacklisting works by creating disable-thunderbolt.conf in
/etc/modprobe.d/
and insert
blacklist thunderbolt
in the conf file you created.
You can blacklist any offending party this way
Save, reboot.
If the blacklist is included in the initramfs — disclaimer: I don’t know — then it might be wise to rebuild the initramfs first before rebooting. 
sudo mkinitcpio -P
Precisely, thank you @Aragorn