E: This reminds me of the concept of the readymade in art, as a way of bringing common objects into the art realm, as well as the concept of the multiple, as a way of bringing art into the hands of people. It seems inevitable that Bruno Munari come up, given that his Cubo ashtray and Tetracono were both early examples of the multiple.
We also see this as a topic of discussion at Documenta 4 (Figure 3) in the essay titled Graphik und Objekte: Vervielfältigte Kunst, loosely translated to Graphics and Objects: Multiple Art. Though with my limited knowledge of german, this is about as far as I can get.
Marcel Broodthaers' plastic plates (Figure 4) also come to mind as pieces of art and graphic design that borrow from cultural readymades (punctuation, signage) and create something new from them. I'm curious how this endeavor differs from the idea of producing art that is meant for humankind as the end product is some object that acts as or resembles a "nonart" object.
Design in particular is fascinating due to its role as an "applied art" or "service industry." Rarely is it given a definition as generous as yours in which design can be seen in the context of art. I run into this issue with many people I talk to who assume that design is synonymous with advertising and marketing.
Maybe a better question is: what is it about art and the philosophies associated with it that make us want to associate graphic design more closely with that discourse than a necessarily commercial one?