Because giving your best informed estimate helps drive policy decsions and could save lives. Why should he be silent?
And how should we interpret this prediction in the context of the 1918 Spanish Flu pandemic,
Well the Spanish flu is proof that deadly pandemics can and do occur. This pandemic is much worse than the seasonal flu, but not expected to be as bad as the Spanish flu.
Because giving your best informed estimate helps drive policy decisions and could save lives.
Has FR become DU? This is a literal Democrat talking point of many years. If it saves just one life! Blah, blah, blah.
It has yet to be demonstrated that this is much worse than any other flu season at this point in time. (I am guessing that it will be, but so far that's not showing up in the overall death rates from pneumonia and influenza.)
https://www.cdc.gov/flu/weekly/
Fauci has lived (and thrived) in the swamp long enough to know that exceeding expectations has it's rewards, and failing to achieve expectations may be punished. (Sometimes.) I'd suggest that it's implicit that total US deaths will likely be less than 100,000-200,000, and possibly significantly less. (99,000 or fewer.)
At 100,000-200,000 US deaths, the US death total would still be only 5% to 10% of the mortality that was seen during the 1918 Spanish Flu pandemic.