Regarding the support people... Keep in mind that these folks have been being bombarded every minute of their workday with "when is my Mavic shipping" since Oct 15, if not Sept. 27. And since their bosses aren't giving them tools to determine it, it's got to be really frustrating for them. I'm surprised they've maintained professionalism as well as they have.
And keep in mind that every modern company logs support queries from customers. So if you've pinged these people multiple times -- once weekly or once daily -- and been told they don't know, they have a record of that.
They wouldn't have these issues if DJI had given them a method to estimate shipping, but fact is that they haven't, and that decision was above their pay grade.
So maybe keep that in mind before chatting them daily or getting angry if they tell you they can't tell you. DJI's doing themselves no favors from a PR standpoint with their lack of transparency on shipping estimates, but the front-line people you're dealing with on the Internets and support phone lines aren't the ones making these decisions.