Based on the reference in the application confirmation email, the plan has always been to announce next Thursday, 4/1. So, I would expect it to be the same or earlier unless they send an email update (and I would have expected that to already come like the ones from the Ivy League schools that noted a delay to 4/6).
"Your 2020-2021 Regular Decision application to Duke University has been received. We’re delighted you applied and look forward to reviewing your application.
Between now and the April 1 admissions decision announcement date, we will send a number of important messages that may require further action on your part."