I submit computer science departments have enough expertise to operate a graduate data science program. Maybe not every CS department, but enough. It is interesting that the actual stats departments do not encompass all statistical knowledge and expertise. More specialized experts in econ, finance, many fields of social science, not to speak of all engineering fields and computer science and applied math. Data science predates modern statistics; Laplace used least-square to ignore "the God hypothesis;" the function-approximation view taken in many engineering fields is just as powerful as the statistical approach.