You do not need the DDP to have Disney ADRs. You don't even need to be staying at a Disney hotel, and none of the dinner reservations are linked to your hotel or your dining plan. When I cancelled my son's May hotel reservation, I asked what would happen to his ADRs because he was still going to Orlando/theme parks just not staying at Disney. Disney reservations told me that all ADRs are linked to the Phone Number you give them, not a hotel reservation (because anyone can get Disney ADRs - you do not have to be staying at a Disney hotel)
The only reason they need your hotel confirm # to book your dinner reservations is to verify that you're eligible to book 90 + 10 if you're a Disney hotel guest.