If the federal government would have told them floats may kill someone, they likely would have cancelled the parade.
I could be misinterpreting this, but not for nothing- hind sight is 20/20. New Orleans' economy is basically dependent on tourism, and Mardi Gras is one of the biggest draws of the year. There's a lot of problems with my state's government and New Orleans in particular, but the decision to cancel and then enforce that order on one of the mainstays of people's livelihoods
when there wasn't a lot of information or widespread concern among the general public at the time about coronavirus would have been an impossible task without wider support at higher levels. I won't go further into politics here.