I've opened an XDA thread in the past week explaining how Samsung completely got rid of the OEM Unlock feature in One UI 8.0. Unfortunately every device which runs One UI 8.0 is affected, so if you want to keep your bootloader unlocked you must stay on One UI 7.0 or below until a new solution to flash custom binaries is found (currently the only way would be via a EM Token just like on USA/Canada devices).

@salvogiangri So, we should wait before upgrading ? Or is it safe aslong as the bootloader is unlocked ?

@salvogiangri
You mention the possibility of installing unsigned files using
EM TOKEN
I searched all over the web for information about this method and it seems that the last time it was available for purchase/use was in the days of the note10....
Is there actually any possibility in the world to unlock a bootloader?
Paid or in any way

@salvogiangri So, we should wait before upgrading ? Or is it safe aslong as the bootloader is unlocked ?

Any device updating to One UI 8 is permanently losing the ability to unlock the bootloader, even if it was unlocked previously.

@salvogiangri ...
Is there actually any possibility in the world to unlock a bootloader?

The only method possible right now is to downgrade the bootloader executable containing the unlock code to the One UI 7 one, which is abl.elf for Snapdragon devices, sboot.bin for Exynos device and lk-verified.bin for MTK devices. Flashing back that specific file via Odin will restore the unlock feature. Please note that this method will stop working the moment Samsung will bump their rollback protection bit in the firmware, so my personal advice is not to update to One UI 8 unless you're going to flash a custom ROM which can run just fine with an older firmware.

Ok, if I want to have One UI 8 and higher, I have to lock the bootloader, but unfortunately, the Knox flag will remain. Is there a chance for the patch to work with Shizuku?

I think its really dumb from Samsung to do that. Its my device and i can do what i want with it.