The word 'though' sets up a contrast: the film's implications were feminist, but its existence came before her active political involvement. Antedated means preceded in time — the film came before her active feminist political work. 'Preceded' is the synonym pair in the original. 'Cloaked' means concealed — that would mean the film hid her involvement, a different meaning. 'Portrayed' and 'renewed' don't fit the temporal contrast.