Like I said earlier I expect Apple to under promise and over deliver on shipments of these, would be odd for them to not just have a boat load of stock of all variants ready to ship on launch, and it’s not like an iPhone that will sell out on pre orders immediatelyI went with an 15" air for the first time, as a supplement to my primary work machine and since the M4's are similiar to M1 Max series which is my primary. Didn't order on day one, so my order was set to delivery 20th march. Funny enough I got an text message from UPS that a package is expected from Apple on the 13th, and tracking shows it's been shipped and on it's way — Apple's website still says, preparing for shipment with 20th as delivery 😂 fingers crossed it arrives a week early, and first time I've gotten an delivery tracking before Apple officially says it's been shipped.
I’ve had a couple things ship early from Apple in the past and the tracking on the Apple site just stayed on preparing for shipment or shipped for ages and never really ever goes to delivered even after delivered, good luck!