Singing is not really a big issue within the Borg. If I recall correctly, they did not sing at meetings in Mexico for a number of years due to some sort of governmental registration thing that the JW's were like a club and not a religious group or something. Don't ask me to look it up but it has been posted here several times over the years.
As DesirousOfChange mentioned, the Borg is laying low. IMO, that is a smart move in a political sense. If you had half of a congregation affected with the virus, it would be considered "bringing reproach on God's name" or some other thing when it was broadcast on the news and throw a negative light on the Borg.