Along with a traditional XP system, players can garner Street Cred by completing side missions and jobs in the city. The player’s reputation is then used to unlock access to new vendors and contacts throughout Night City, allowing them to complete new missions.
That seems like a sensible approach. It sounds like what you are unlocking is "Questgivers" basically, who give you access to new jobs. That way of doing it provides context. It makes sense that certain people aren't going to trust you until you've made a name for yourself in ways that matter to them.
But I think the question remains regarding free roaming. Can the player still physically enter a district even if there are very few people there interested in talking to V?