I think it's okay for furries to show up to events that aren't exclusively for furries if it's a furry adjacent thing. Furries are sort of seen as an extension of general nerd culture so showing up at ComicCon in a Fur Suit is fine. I think think going "oh there's costumes, I guess I'll show in a fur suit" even when it's a cultural festival that has nothing even tangentially related to furry culture seems a bit gauche.