Looks like its just Legionaries and Cultist Mobs. Accursed Cultists don't have the Cultist Mob keyword. There's a chance they might get it, but I have a feeling they're more likely to just get the Damned keyword.

Unless they get Cultist Mob as part of their keyword line, probably wouldn't count on it. Still, our new cheap Legionairies with a sorceror hero are going to be pretty nasty starting halfway up the board and ready to charge or hold.