What do you mean by "content"? Unique gear? Missions? Unique vehicles? NPC interaction? Technically the game has many of these things already
Well, there could be a lot. Unique abilities based on your life path for example.
Maybe corpo could scan people and get info about their status in society, bank account status etc. You could then use this info to blackmail people or force them to do your bidding. "So I see you've twenty grands eddies missing for your nice wheels and that suit. How about you do EXACTLY what I say and I can help you extend the payment time.. Or would you like the Company X loan sharks to pay you a visit?".
Could enter your corpo HQ and make decisions how to deal with people living in certain areas. Rise land taxes, ban or push certain goods. Maybe even implement corpo-competition and a threat of 5th corpo war between your rivals.
Street kid could utilize gangs to a high degree. You're the know-it-all city dweller after all. Join the ranks of NC gangs or just hire your fav one to wreck havoc for whatever reason. Gang wars would fit here naturally too, like corpo wars for corpo path. Just the emphasis would be more on ground level guns blazing whereas corpo would play the money/influence game first.
You could have unique abilities for combat, like special reflex boosters and/or ability to craft drugs or something. Things that would come to you naturally as you're fluent with the NC underworld.
Nomad could have natural toughness, maybe radiation mutation due to badlands? That, or affinity for Big Guns. Nomad-only rocket launchers, yessir! An easy fit would also be to call your nomad family buddies (yea I know you're supposed to be a loner) and nomad-specific family/clan disputes can also play a big role.
Stuff like this I just made up on the fly. So if someone would sit down with all the lore they have, I don't doubt they couldn't come up with all kinds of neat ideas. Problem ofc is that all those nice & cool things take time to implement. Time CDPR has to put into actual bug fixing for now.
Maybe DLCs down the line...