Sex is NOT “assigned at birth”, it is DETERMINED at birth by identifying genitals and or chromosomal composition.
As verbs the difference between determine and assign is that determine is to set the limits of while assign is to designate or set apart something for some purpose.
Sex is not “determined” at birth either. It occurs when life begins, at the moment of conception.
These other terms are created and used by fringe people desperate to imagine them selves as mentally healthy, when actually they have serious problems.