As walker6168 said: hard to answer without the source article.

I'll add that their data had better be pretty solid as there has been extant genetic caracterisation of pathogen material from mass graves from medieval Black Death epidemics (source).

However there was a suggestion that an Ebola-like virus might have been involved (see: Scott, Susan and Duncan, Christopher; 2004. Return of the Black Death: The World's Greatest Serial Killer) based on circumstantial evidence and rates of pregression. Given the quite conclusive data from Haensch et al. (2010) which have actually IDed real Yersinia Pestis DNA in the mass graves to the extent where they could caracterise the strains in presence, that theory has been put to rest (unless your source refers to more recent work and actual paleo-viral samples).

An article a bit broader than the excellent source provided by /u/Gargatua13013

There are people who challenge the idea that the Black Death was caused by Y. Pestis but they are a minority nitpicking for reasons to reject all the evidence supporting it. It's not impossible they're right, but they're probably not.

Not only is there now strong genetic evidence that the Black Death was caused by Yersinia pestis, but recent studies have done similar analyses for the Plague of Justinian, which had been the subject of an even more vigorous debate about its causative agent than the Black Death. They first showed that they could find Y. pestis DNA in plague victims, and in a later paper sequenced the entire genome and showed how it was related to other Y. pestis strains.

The fact that studies on both pandemics came to the same conclusion makes me fairly certain that both plagues were in fact caused by Y. pestis. Also, as a history nerd who ended up going into microbiology and genomics instead of history, it makes me extremely happy that my field has suddenly become relevant to history and anthropology.

The consensus as I understand it is that there is enough evidence on both a scientific and historical/archeological basis to go with y pestis as the plague. The key limitation, though, is that the historical record is both difficult to interpret as a result of very different forms of records that bear little resemblance to modern medical symptom detection, not to mention only erratically mentioning things that you'd think would be a pretty big deal like swollen buboes and the like. The considerably higher kill rates (50-70%) of the historical disease as compared to well-recorded outbreaks in the 19th century and onwards (5-20% and straightforward quarantine effectivity), and there are also questions about weather issues for transmission vectors (ie fleas being effective out of season) and the generally insanely high rates of contagion described historically. That leaves us with a couple of possibilities:

-Y Pestis had little to do with the plague, and it was actually some other source for the epidemic for which we have nothing but conjecture and a startlingly convenient confluence with contemporary headline-makers. This is where many of the headline grabbers come from on this topic, which is not to say that there aren't credible arguments in its favor.

-Y Pestis was present and a key variable in the mass death events of historical plagues, but worked in combination with diseases, viruses, or other factors we have not yet been able to isolate in order to be extraordinarily lethal and contagious. That attempt to derive "combo" disease effects from the past is one that Mirko Grmek defined as pathocenosis.

-Y Pestis was present, but in a more dangerous form than it is today despite direct but controversial DNA evidence that points to a similar genotype to the modern disease.

Of these, I find the second option the most compelling, and the first option the least, with the third being out of the question until any evidence for it is found. A key academic advocate of "anything but y pestis for the historical plagues" was Samuel K. Cohn, and he's probably worth looking at if you are interested in (historically derived) alternative theories. His work is pretty controversial, but in the way that even if you disagree with his conclusions you learn a great deal from his meticulous analysis of textual primary sources.