On Friday, 4/14, the DJI website said it would take "1 working day" to ship a Mavic back to me. I thought that meant they'd ship it Friday or - at the latest - Monday. I should have known better.
Today, 4/18, I called DJI. After waiting 30 minutes, a nervous-sounding man with limited English language skills told me that my replacement Mavic would probably ship within 3 to 5 business days. He explained that this was a good deal for me, because DJI is taking that time to do a quality check on the replacement, to be sure it works. (What a concept!) When I asked whether I could pay extra and get faster return shipping, the answer was, "no".