The idea you're suggesting boils down to a fairly common issue: the respawn cooldowns for mobs and NPCs. There will be people who create hacks to farm solo PVE camps almost automatically at times when no one else is around. There will be a few small tweaks to avoid detection by anti-cheat software, but overall, this will be used for RMT. Even if it doesn’t yield much profit, people will do it and buy software to make it happen.
So, if it’s a matter of cooldowns, maybe specific times, or certain zones turning “blue” as you suggest, while others remain “red” almost all the time
Personally, I'm having a hard time understanding the general concept of the “aggressive flag” in relation to the other ideas he proposed about group creation. I just can't seem to connect the two. I haven't played the game, so I'd need someone to stream it for me and explain it.