I think you answered your question. "Squishy"
They are nerfing kata for the new season not for her being OP is what i got from there post.
i don't think akail is that squishy[ARMOR 20.5 (+3.5 a lv), MAGIC RES. 30 (+1.25 a lv)], leblanc [ARMOR 16 (+3.5 a lv), MAGIC RES.30 (+0 a lv)], thats squishy, i don't even have to batt a eye to kill her, but akail + gun blade allows her to heal a fair portion of her hp and spell vamp nonsense with one of her skills. they should either lower her armor and mr to leblanc's level or remove her spell vamp on her skills. (not to mention that dangerous game mastery grants 5% hp back per kill, i probably missed some stuff too but all this is adding up people)