Agree 100%. I've been around these boards since at least the 4S and this has been the case each time. This is an intentional tactic which serves two purposes: 1) it encourages more demand by making people think they have to order as fast as humanly possible and 2) makes people happy when they get their phone sooner than expected.
You're going to get your phone sooner than they're quoting.
I looked back at my email and calendar and I realized that I have gotten every iPhone on launch day since the 4s! I sort of can't believe it, but it seems to work out each year!
3g: waited in an interminable line at an Apple Store and got the phone on launch day
4s: I walked into a VZ store on launch day and walked out with an iPhone
5: pre-ordered from VZ and got delivered on launch day
5s: camped out overnight at an Apple Store and got one of the only gold models they had
6: pre-ordered from T-Mo and arrived on launch day
6s+: pre-ordered from T-Mo and arrived on launch day
7+: Hoping VZ doesn't ruin my perfect streak