That's— a really weird take, tbh. Forbidden Scrollery changed Marisa's characterization not one whit. You could make an argument that Wild and Horned Hermit portrayed her as devoted to Reimu, but I think that's an artifact of the whole manga being structured around the shrine (and Kasen's disdainful view of Reimu).
Anyway, ZUN is still writing everything official, so blaming a work-for-hire artist for character changes, or worse yet, fandom trends, is kinda gross.