I thought we already knew this. A quick search found this from 2018: https://pmc.ncbi.nlm.nih.gov/articles/PMC6206193/
All giraffe (Giraffa) were previously assigned to a single species (G. camelopardalis) and nine subspecies. However, multi‐locus analyses of all subspecies have shown that there are four genetically distinct clades and suggest four giraffe species. This conclusion might not be fully accepted due to limited data and lack of explicit gene flow analyses. Here, we present an extended study based on 21 independent nuclear loci from 137 individuals. Explicit gene flow analyses identify less than one migrant per generation, including between the closely related northern and reticulated giraffe. Thus, gene flow analyses and population genetics of the extended dataset confirm four genetically distinct giraffe clades and support four independent giraffe species. The new findings support a revision of the IUCN classification of giraffe taxonomy. Three of the four species are threatened with extinction, and mostly occurring in politically unstable regions, and as such, require the highest conservation support possible.
Edit: this 2021 report has a nice image:
Could it be that we had to confirm the results? Your quote suggests that it was open to more research at that point, while the article says after a decade of research it is now official.
It’s interesting to have more insight to the process - an important reminder that these things don’t happen overnight.
You are absolutely correct. It took time for the evidence to be reviewed, accepted, and for the new consensus to be codified. Mostly, I wanted to let folks know the headline was a bit click-baity and give some examples of how we got here. I wish we were wired to get the same excitement from titles like, “Zoologists agree: Giraffe are four species – not just one!” with an article that gives more credit to all the research.