Just checked FedEx app and I see my iPad shipping from China
FYI as of right now Adorama shows the 12.9 Space Gray 256GB WiFi-Cellular in stock if you are looking for one.
I ordered one myself and will cancel my Apple order tomorrow once I confirm the Adorama order will ship tomorrow. They have usually been punctual in the past so no reason to doubt, but... trust but verify, right. Earlier today I noticed the local MicroCenter also had one in stock so maybe a big retail "wave" is coming this week.
but my fedex app says they picked it up already!
I got my official shipment notification from Apple today.. should be here Friday if all goes well according to FedEx current estimates and Apples email. However, the text I received from Apple says the 31st... I'm going to hope it's Friday and not delayed by another weekend!!