This is one of those "chicken and egg" situations-- did civilian attire influence military uniforms, or did military uniforms morph into civilian wear? I think it is very much the case that since uniforms by and large are based on the civilian clothing of the period, that the two modes of dress (civilian Highland attire and Scottish regimental uniforms) really developed more-or-less simultaneously, with civilian attire generally a decade or so in advance of the military.

Had proscription never occurred, it is likely that today's Highland attire would look much as it does-- seeing as how civilian Highland attire (the kilt aside) is really nothing more than slightly modified "ordinary" civilian dress.