The whole line about custom PCs making their own story is just PR speak
I know exactly what to expect. I don't give a shit. i played DOS 2 both with custom characters and premade origins. I never found it a big deal. A couple of sidequests are the main difference between the two, and you could get plenty of "customized reactions" based on your background tags etc.
People who claim the experience was massively different sound delusional to me.