Answer: I would say false.
Explanation: From my understanding, street artists make more of what would be considered visual art, or maybe fine art, not necessarily commercial art. I could be wrong, but that is my understanding of it.
The medium looks to be an oil paint. The value does not vary in contrast and the color stays on the dark side as opposed to lighter colors/shades
Pastels are chalk. It is dry pigment, mixed with a dry binder placed on a textured surface to hold the pigment to the paper. It doesn’t involve any liquid of any kind. Acrylics are a dry pigment, mixed with a liquid binder placed on pretty much any kind of surface that is properly prepared with gesso or some kind of acrylic medium. Water or liquid mediums are involved in the application of the paint. Acrylics cannot be put over top of pastels as the dry pigment doesn’t allow the acrylic paint to bind to the substrate. You can put pastel over top of acrylic ONLY if you use an acrylic ground medium specifically designed for pastels. It kind of feels like sandpaper after you apply it and it dries clear. You will have to put a fixative on the pastel if you are using it on a canvas substrate, and that is a whole other topic of discussion.