I don't think it's anything new to use Silence-based actions in high end content though is it. Off top of my head, o7s required someone to Silence Ultros from using stoneskin and I think Wreath of Snakes has something similar with the first group of adds? There might be other duties that require the action but seeing as ranged DPS and NIN could fill this role, it wasn't so important for tanks to do it but the mechs still existed.