My understanding is the "charge for deliveries" is a charge for packages SHIPPED to the resort -- such as through USPS, FedEx, UPS, DHL, etc. Those get a $5 per package/box/envelope charge, possibly more at the convention resorts.
For actual deliveries -- i.e. the company is directly delivering to Bell Services -- such as Garden Grocer and Amazon Prime Now, my understanding is there is no WDW fee at this time. Of course, in most cases the companies will have their own delivery fees as part of their service.
I believe with Amazon Prime Now you can arrange to met with the delivery person, but at the lobby/porte cochere, not at your room. There are a number of posts on here that talk about Amazon Prime Now and I recall some talking about meeting the delivery person.
SW