Unlocking the bootloader and using TWRP/similar is not rooting. Installing Magisk/SuperSU, or similar is what roots the device and that is usually an optional second step after installing the ROM itself.
But alright, doesn't seem to be the exact same situation as me then, but thank you for the info on your experiences
Any others who does not have root who might be able to install the MitID app and check it out? (Don't even know if it is available outside Denmark?)