i just got the iphone 15 pro, and it says it wont be shipped until october 6th... why is that?

The 22nd is when the “first” iPhone 15s will become available.

We can’t say for sure re: the details of your particular phone; but it’s likely tied to the specific options you selected; and/or the shipping logistics required for delivery.

It’s unlikely if Apple’s delivery carrier(s) could even physically deliver ALL pre-ordered iPhones on the 22nd.

Remember you are not asking Apple here. We are other end users with no access to Apple's internal sheduling or shipping records.