My heartbreaks have all been with ordering.
Last year I was caught out by the Apple Card debacle, even though I was on the iPhone Upgrade Program and had set everything up before the morning of ordering.
Previous years included my last purchase through AT&T (I'm now on T-Mobile) was canceled with no explanation and no turning back. Orders at that moment were backordered a month when I got the bad news. I ended up getting launch day phone at Best Buy that was not the color or storage I'd have preferred- found out later that they'd tacked on a $50 charge of some sort without mentioning it, but I did get it back when I asked them to price match to Apple's price.
I occasionally get the "we missed you" notifications when i was sitting in the room with an open window to the driveway. Part of why I now go to the CC to pick up my phone.
Have fun and good luck!