I'm not expecting to see any status updates until the 31st.
First, it specifically said on the website that it's not shipping until 3/31 so that pretty much ensures there's no chance of receiving it on the 31st. Second, stock for anyone except Apple is typically pretty iffy upon release. I've had iPhone and iPad pre-orders from AT&T and Verizon get delayed by weeks to a month, too. Carriers and retailers often don't know just how much stock and what configurations they'll receive until they receive shipment. If you want your devices right away, bear that in mind for future purchases. Safer to buy directly from Apple.
If you want better logistics now, perhaps you can just cancel your B&H pre-order and order from Apple. Their shipping times are fairly accurate (actually has quite a bit of padding) and Apple.com and Apple Retail Stores get priority.
I guess despite all the folks on here bemoaning the iPad Pro 9.7 only having 2GB RAM and the $100 price bump, the device was more popular than expected.