Yeah, trying to do the basic math on the implications of these figures...[Not claiming they're true, that's a different question]
The article says 221,000 infected at a 2.8% rate, in "early April". So they're assuming a 7,892,857 population. Currently, we have 601 Deaths total in LA[1], which we can assume are a result of early april event on April 20. So a 0.002% "fatality rate" relative to total exposures, "Woohoo" (NOTE, this is an optimistic figure implied by this study, the standard 2% [edited] previously claim but still not equivalent to the flu, which has 0.2% [edited] relative people who get sick). Now, with weekly doubling: 221,0008 = 1,768,000 infection now = 22.4% - > 4808 deaths. However, past 10%, we can ask whether we start reaching saturation/diminishing returns. But that is a key question.
-- Let's look at NYC. There we have 14,500 Death. Using the article's implied figure, 14,500/ 0.002 = 7,250,000 infected on April 1, out of 8,398,748. So this implies an infection rate of 7,250,000/8,398,748 = 86.32239%, which, in fact, seems very implausible and which implies; a higher death rate among "vulnerable people". Maybe we're about to hit full saturation with NYC and see an immediate decline.
Now, the other bad* scenario is the possibility that a lot of sickness and death NOW is being driven by reinfection, that exposure isn't giving much immunity at all and instead of the unexposed dying, what we're seeing is the re-exposed dying and with this dynamic, the death rate settle into a steady and unacceptably high level. Note that Italy, which has seen a high death rate, hasn't a strong drop-off at all, just gradual plateauing. IE, guess what, one possibility is "herd immunity" just doesn't exist for this virus.
Anyway, time will tell, literally a week will tell if NYC has enough fatalities to make this 0.002 exposure-to-death rate numerically impossible.
[1] covid-19.live
Edit: corrected conversion ratio to percentages.