Like Kosuke's 2D waifus, Ibarada is clearly being tsundere.
Kosuke just started spinning things in a romantic direction, Ibarada only just relieved her trauma.
She needs more time and effort from Kosuke to properly be rehabilitated for a romantic relationship.
Also, Kanade's love for Yukimura was being set up all throughout the series, he was always there for her when she needed help. It's not the author's fault that you didn't see it coming, it wasnt forced for no reason.