There are two events in and around Swordcross Outpost
Defend Swordcross command post from ghosts
Defend Plagan Swordrend as he repairs the turrets
I have seen these working and am aware of their “normal” repeat rate.
They are not working at all now, possibly due to the bugged <Protect the siege team as they approach the wall> but possibly just bugged in their own right.