A couple things...
First, git doesn't especially solve problems that CS majors have until they are near the end of their courses. The need to manage collaboration, organization, and change in a code base is trivial until pretty late in a CS program, and typically never gets past basic.
Second, the context here is the git command-line interface. People can and do use git extensively without it.
Third, git's not exactly perfect. Personally, I'll be a little sad if git remains the de facto standard source control in the long term... it's not bad, but we can do better.
I think lack of knowledge of git commands in a CS grad would be essentially uncorrelated with future professional success.