Yes it'll still work without them even if your nuvi is usually supplied with VCJ and G2S files however obviously with decreased functionality. See initial post for what they do.

It's worth pointing out that most ancillary files (other than some outliers like, for example, ASR SRD language files which must be onboard) will also work if placed in a Garmin folder on a media card, e.g. "sd:/Garmin/JCV/******.jcv" or "sd:/Garmin/POI/******.gpi" and so on.