this preprint article is arguing that the strains are showing the potential for dramatic differences in mortality rates - indicating that the virus that showed up in italy and traveled to new york may be much deadlier than the one that came to the west coast from china.

and, that may be a kind of epiphany in analyzing the data.

https://www.medrxiv.org/content/10.1101/2020.04.14.20060160v1.full.pdf