There are comments further down explaining how the containers likely weigh substantially more than the lift capacity of heavy lift helicopters. They'd have to partially unload the contents of each individual container first.
And if you're unloading, the human labor cost to unload the whole container is probably cheaper than the cost of running a fleet of helicopters for weeks to months.
And if you're unloading, the human labor cost to unload the whole container is probably cheaper than the cost of running a fleet of helicopters for weeks to months.