Update 9/9/21: Being offered again.
Update 1/25/21: People being targeted for 0% APR again, can check by using the chat feature.
Periodically Discover offers some cardholders additionally offers when asked, for example:
Currently Discover is offering some cardholder 0% APR for 12 months. To see if you’re eligible you need to chat with a Discover representative.
Hat tip to reader Matthew
Source: doctorofcredit.com