I reckon the govt may impose a lockdown, which will leave the streets clear for Le Tour. The French will welcome the chance to stay at home and watch/ stay at home to ensure the Tour goes on.
Predictions:
A rider will abandon and then test positive a couple days later. Another member of the team will test positive during the race.
Bernal and Roglic will not make it to Paris.
The Tour won't be finished early to ensure a French rider wins.