C0 basically served as an introduction to C, with contract annotations. The contract annotations were used to enforce more thinking about your code (i.e. proving your code worked via pre/post/loop conditions). There were still pointers, there was just a bit of syntactic sugar surrounding it.
About 2/3's through the course we switched to full-blown C, at which point we had to learn pointers. The intro to computer systems course (think malloc, proxy, and buffer overflow labs) used C as well, and that in turn required us to use pointers. There's no "losing out" on learning pointers. It's basically a step-stool to C.
At the time, I had a pretty good grasp of pointers and thought C0 was a bit silly- I'd never used contracts in my life. I currently work as a full-stack web developer (bit of a twist from my intended path) and I've never seen anyone "write out contracts" like I did in C0. I now think it was a valuable exercise in that it forces you to define the parameters that allow your code to run.