About Fiora's new splash arts and splash art "updates" in general
First of all, why did anyone think the old ones needed an update? They were perfectly fine. Ironically, the only Fiora's splash that did need an update* was untouched. She still looks like a 50-year-old after facelift. The new ones, other than in my opinion they just look worse, are too anime-like, which doesn't fit the general style of champion splash arts in LoL.
*Or "un-update". Since you're un-reworking Kog'Maw, while you're at it you could un-update the splash arts that were replaced by worse: Vayne, Swain, Fiora, Musketeer Twisted Fate, Divine Soraka, Frostfire Annie, Irelia, Spectral Fiddlesticks, Boneclaw Shyvana, Rammus, Xin Zhao.
Some other splashes that do need an update: Tristana, Alistar, Galio, Janna, Malphite, Warrior Princess Sivir, Bandit Sivir, Gentleman Cho'Gath, Corki, Amumu, Singed, Imperial Xin Zhao, Kassadin.