Rachel Miles, writing on The Bibliomagician on the new crop of automated tools that spit out citation recommendations:

The Matthew Effect, in which advantage begets more advantage, is exacerbated by automated citation recommendation tools. These tools’ algorithms are based on current and past citation practices and function similarly to Google’s PageRank, retrieving the most “popular” results rather than the most relevant or accurate ones. In academia, scholarship from the Global North, in the English language, from high impact or top ranked journals, and scholarship with higher citation counts may be further benefited by these recommendation tools whereas publications in non-English languages, from the Global South, and in newer or emerging journals will be disproportionately disadvantaged. 

It’s a great point, about cumulative disadvantage. Miles cites a number of other drawbacks of the tools, black-box algorithms, lazy citing, and confirmation bias.