Varies, but usually inside the terminal. But they still need to be handed over to a human so don't expect to get away with overweight bags.
Posters were looking for the convenience of curbside luggage checkin without paying Delta's $3 /bag charge. The wording in the website isn't clear how that would work but it did say passengers who check baggage online are exempt from that fee.
Delta's website is still promising 2 checked bags, for free. Not really fair to expect passengers to have to read the CoC and then decide which information is accurate. Other airlines grandfather passengers with reservations, absence clear information to the contrary Delta passengers might assume the same.
I'm beginning the wonder if this is intentional. Delta may be looking for some quick revenue from passengers that aren't aware of the new rules. I think we can agree many (probably the majority) of passengers will cope with a one bag rule as long as they're aware of it in advance. One poster was refused a requested refund, was told the baggage rules are not part of the CoC.