It was a devastating choice; since most US bands who had been invited to participate had already canceled, they had worked around the world to arrange bands to come perform.
Many contingency plans had been worked out - banning any street view watching of the parade, no grandstands, TV corner would still be there, but without any live audience.
But ultimately, the problem they couldn't overcome (but they tried various experiments to see if they could) was that it takes thousands of volunteers to decorate the floats for the parade. Many of whom have been doing it for decades, and most of whom are in the 60+ demographic which puts them at the most risk.
They couldn't come up with any reliable barrier that would work with the floats, and this past parade, quite a number of volunteers came down with influenza after the parade, killing 7 of them.
Thanks. It sounds like you have inside info.