The growing popularity of preprint servers, notably during the Covid-19 pandemic, prompts a reevaluation of their role in science communication. This study delves into discussions and commentators on preprint servers, applying systems theory and boundary objects to scholarly and science communication. The approach is to analyze a sample of COVID-19-related pre-prints of bioRxiv and medRxiv and examine their comments and associated Twitter posts. Using mostly quantitative methods, the data was split in two groups: comments by biomedical peers and non-peers inside and outside academia. The results show that almost half of the comments can be attributed to peers, who also discussed different topics than the rest of the sample. On Twitter, the proportion of comments from peers was significantly lower, and the social network of academic and non-academic communities is intertwined. In summary, pre-prints can be seen as boundary objects that stabilize rather than blur the distinction between science and non-science. In this way, they promote the dissemination of knowledge and inter-disciplinary discourse. However, communication between scientists and the public remains ambivalent due to high barriers to entry. Challenges remain for integrating discussions into the peer review process without diluting standards and encouraging engagement from experts and laypersons.