They are still in the new codex, don't worry about them getting removed!
as for them being on the tabletop.... I think you need to realise that they are kind of a risky tactic. Everyone will agree that the disadvantages of Guardians is how fragile they are and the short range of their weapons. Storm Guardians get an even shorter range weapon (Shuriken Pistol) and get no extra buffs. Mind you they can have fusion guns

. Overall, a risky strategy, but definitely something to consider if you don't have that many
CC Aspect Warriors.