Have these been disabled?
Yes. Players had been laying down foundations to lure in bosses, so twenty-thirty thralls could swarm them, then the player farms items and greater essence.
Is there a way to turn them on in a private server? While not with 20-30 thralls we do build an arena and kill them for pages and cores and for battlepass challenges. Do the ones in the pools count as storm bosses? If not they need to remove that challenge.
In the Pools do count. Possibly at The Fractured Citadel too.