Concerns about selective exposure and disinformation in the digital news environment have brought the concept of news diversity to the forefront of academic debates. Despite its growing prominence in scholarly work, however, news diversity often remains hard to grasp. The current paper aims to re-assess what the concept of news diversity means in an evolving news ecology. To do so, we draw on three dominant conceptualizations of news and media diversity. We use their strengths to unravel the variety in conceptualizations of news diversity and to explain how diversity is built on different conceptual and normative assumptions towards news media and democracy. Based on these insights, we perform a systematic literature review in which we map the current communication science literature that address news diversity. Results show that 43 different news diversity dimensions have been used in literature, indicating a form of academic cherry-picking with both normative and conceptual implications. We propose a way forward by formulating recommendations for future diversity research. This includes a shift to a more theoretically grounded approach in conceptualizing news diversity, a call for interdisciplinary research, and giving the idea of normativity a more pronounced place in research on news diversity.