This claim is true and has evidence to back it up.
The truth is, dark chocolate can have health benefits when consumed in moderation. There is research linked with dark chocolate improving the health and well being. The blog article that was linked states that consuming dark chocolate can help protect against cardiovascular diseases. Although this is true, the blog article itself does not provide enough factual evidence to support this claim. But, I have found a credible research article that helps support this claim.
According to the National Library of Medicine, "regular consumption of dark chocolate will lower the occurrence of high blood pressure. Thus, it delays the occurrence of Cardio Vascular Diseases...", the article contains factual evidence and has been peer-reviewed by multiple professionals, overall supporting this claim and includes the fact that dark chocolate can overall improve your health when consumed in moderation.
Samanta, Sharmistha, et al. “Dark Chocolate: An Overview of Its Biological Activity, Processing, and Fortification Approaches.” Current Research in Food Science, U.S. National Library of Medicine, 15 Oct. 2022, pmc.ncbi.nlm.nih.gov/articles/PMC9589144/#sec4.