There will be something like a karma system in the game, with red-flagged players unable to do certain things like enter certain NPC towns. That said, there can be NPC factions that are friendly to red players if they’re allowed to flourish, and even factions that will not interfere in a player murder or will actively attack players with good karma.
Content retrieved from: https://massivelyop.com/2021/05/05/profane-talks-about-mitigating-pvp-stagnation-avoiding-zergs-and-territory-control-mechanics-in-an-ama/.