NPCs have been programmed to attack players for a long time now.
Not specifically for iEra, but in general.
The Classic baddies have been around for a good few years right?
To script them to attack you with a gun rather than a sword is no big thing.

But to put this in front of the bank on the general gmap would be a nightmare for regular people.
Players just blundering by would be caught in the middle of some intense NPC/Player crossfire.
And then the complaining would begin.