Based upon how close most of the tables are in restaurants (looking at you Le Cellier, and you San Angel Inn), it would not surprise me to see that the capacity of table service restaurants is only 25% with social distancing. With free dining promotions, you're pushing people into table services. With DDP, you're pushing people into table services. The only way there will be enough capacity to feed even the reduced capacity is to eliminate DDP and free dining promotions.
In addition, with the lottery (they call it reservation) system to get into a particular park, you can't guarantee that you'll be able to have a meal in the park on any particular day because you aren't guaranteed entrance into that park. So, in-park dining reservations had to go. Because everyone would have booked a backup reservation outside the park in case they didn't win the lottery to get into the park they wanted, that means outside the park reservations also had to go.
It's a set of dominos falling...