Superstore showrunners' biggest worry the week of the coronavirus shutdown was whether a crowd scene would be marred by rain

The Hollywood Reporter

But as the week continued and the World Health Organization declared COVID-19 an official pandemic, showrunners Gabe Miller and Jonathan Green said during their Comic-Con@Home that they came to the realization that they wouldn't be able to film the season finale at all. Green said that he and Miller were "down to the wire" figuring out the logistics of those crowd scenes, but "it became clear it wasn't going to be possible to shoot anything for that final episode."