The shutdown wasn't, and isn't, based on the fatality rate under current conditions as much as the shape of the curve of various medical resources being required (total hospital beds, ICU beds, ventilators, PPE for healthcare workers, etc.), the anticipated speed of being able to bring more online, and the likely impact of exceeding available supply on death rates and other health outcomes, both for COVID-19 victims and patients with other health conditions. (A potential problem which was significantly realized in Italy, where things like ventilators were for a while allocated based on other factors besides medical need, since the number with need exceeded the supply.)
It's important to remember that the fatality rate of a disease isn't a constant, and changes to conditions (like, we can no longer provide ventilators to everyone who needs one) can change that rate.
And the earliest predictions have to be the least accurate, because they're based on the least amount of data. But early on is when you need to act.
https://www.healthline.com/health-news/how-deadly-is-the-cor...
The point still stands is that enough to warrant the current strategy compared with countries like Korean or TW.
I mean there were articles like this all of march. I'm not saying the WHO or CDC might of said something different but lets acknowledge there were articles proclaiming a 3% death rate.
Edit: Removed the term revisionism since I wasn't aware of the historical connotation.