Fan Nickname: Hibiki and Kanade were affectionately dubbed "Nagisa and Honoka 3.0" by the fanbase at first. Said fanbase later came up with "Hibicake and Kanabake" for the duo, "Mephistroll" for Mephisto, "Man Rin" for Hibiki's father Dan due to his hairstyle, and "Cure Samba" for Ellen's Brazillian carnival-inspired getup from episode 5.
Lying Creator: Early on, Toei leaked a blurry picture of two new Cures: Cure Beat ("Uta Nishio", with a different design from the one that eventually appeared in the series proper) and Cure Symphony ("Koto Toudou"). Speculation ran wild over the picture, with a good proportion of the fanbase coming to the conclusion- based on visual similarities, character roles and Theme Naming- that secondary characters Waon Nishijima and Seika Higashiyama would become the two Sixth Rangers of the series. It turned out to be a joke by the production staff, presumably less-than-pleased when a similarly blurry picture spoiled the identity of Cure Sunshine roughly one year prior.
Too Soon: Suite was originally supposed to go on a Darker and Edgier route, but after the March 11th Tohoku earthquake and tsunami happened, the writers changed the story to something more upbeat to calm grievances.
Because of the disaster, a scene in episode 6, in which the Negatone traps Souta in cake mix, the cake mix had the glittering effect added to make it looks less like the fluid.
According to the writers, this is also why the Melody of Sorrow was completed: the creators wanted children who were nervous about the event to relate to their heroines by having something that was on a similar scale happen to them.