In BL1 and BL2 on normal (playthrough 1) and TVHM (playthrough 2) the levels of the missions were “set in stone” (to the best of my knowledge). In UVHM (playthrough 2.5) every mission was based on the character’s level.
Does this continue in Borderlands 3?
It’s probably more complicated in BL3, but I just want to know.