With the two large "whistle masks" that we've seen in this thread (not the small "whistle pouch"), it seems that it would be difficult for the official to remove the whistle from one's mouth to speak, and to put the whistle back in one's mouth to officiate, something officials do dozens of times in every game. But these two large "whistle masks" would do fairly well (though not great) at protecting others and possibly one's self (according to very recent studies).
Not so with the small "whistle pouch", easy for the official to remove the whistle from one's mouth to speak, and easy to put the whistle back in one's mouth to officiate, although not protecting others (nose isn't covered) and possibly one's self.
Of course, an official can wear a surgical mask (protecting others and possibly one's self) and speak freely the whole game if one were to use an electronic whistle.
I finished reading the book
The Great Influenza: The Story of the Deadliest Pandemic in History (the 1918 Spanish Flu), by John M. Barry, a few weeks ago; and I'm about halfway through the twenty-four thirty-minute video lectures of
Great Courses: The Black Death: The World's Most Devastating Plague, by medieval historian Dr. Dorsey Armstrong.
COVID-19 is a pussycat compared to those pandemics, but even pussycats have sharp teeth and claws.