In principle, like the idea of adding a small AoE DoT to arctic blast which was done by the devs. it adds some class identity. Also to remove those noBrainer, spammable stuns in general is maybe not the worst idea (btw, old arctic blast was not a nobrainer at all, it was clunky, expensive and not even scaling with macMagicka).
But the current version on PTS just means that MagWardens have no stun at all, because the range is just ridiculously small, and its impossible to get any benefit out of it. Additionally, its very expensive, and even if you have it permanently active, this does not really give you a chance to actually stun the enemy.