I’m not sure of the timeline exactly, but I used DJICare on a crash with my MPP when it was only about 2 weeks old... Hit a tree and fell 50-60’ to the ground. I can tell you that the cause of the crash was pilot error, but that’s why you buy DJICare anyway.
Anyway, I contacted them by phone and then filed my claim on a Friday afternoon. I got an emailed shipping label late Saturday and shipped the drone to them on Monday due to my schedule. 8 days later I got an apparently new drone on my doorstep. It came with the serial already registerred in my DJICare account. Interestingly, the replacement drone was shipped from Texas.
Hope this helps