It may very well be that it's very easy to spread this virus, but I don't think this incident is a good indication of that. It seems more an indication of how poorly even well-intentioned people understood the contagiousness and what exactly social distancing meant at the time this happened (1 month ago).
Brings up the difference between public health risk and personal risk. Public health perspective you want contacts to be infrequent and importantly short.
That is this evidence doesn't contradict Streeck arguing that formate transmission is unlikely and that it is long term exposure to breathing people that is the real risk. (Or that being in a relatively empty grocery store provides little risk)
(I don't have a clue one way or the other, just commenting on applicability of evidence)
"Members of the choir were already aware of the COVID-19 outbreak in their state, particularly around the Seattle area, which is about an hour south of Skagit County by car. Hand sanitizer was dispensed at the door of the practice that night in March, no one shared sheet music, and people were conscious not to stand too close to one another or engage in their huggy greetings. Also, no one remembers anyone coughing or sneezing, and no one present felt ill at the time. Nonetheless, a huge percentage of people present later tested positive for the virus."
My point is that the original article said that it's hard to get infected. Assuming that everyone was asymptomatic, and there was no coughing or sneezing, and everyone stayed away from each other, it's actually not that hard to spread the infection. In fact, if there was a single person who was asymptomatic and they infected 45 people, that means it's very easy to get infected.