Shock horror, I'm afraid to say nothing is new - fashion is a revolving wheel.
Yes Vetements Spring / Summer 2017 are leading the way in collaborations. There is no denying that they are storming ahead and literally they are chopping, changing, taking design into extremes be it by using a lighter as a heel, extending lengths or adding zips - but everything is to an extreme which is what makes it awesome design and fresh.
Take these 1970 jeans by Teddy McGee, designed to be literally cut in two. you can literally unzip them from the centre front waistband right though to the centre back waistband at which point if you were lucky enough to have two pairs - you could swop legs and re zip them. The point of which was to have a blue pair of jeans and a white pair and swop the legs so that you would have two alternate colour legs.