I’m still showing a Saturday delivery BUT checked my email. This came about 3 hours ago.
On Friday, September 21, 2018, Apple <order_update_us@orders.apple.com> wrote:
Your delivery may be delayed.
Order Number: Wxxxxxxxxx
Your delivery may arrive later than the date shown in your Shipping Confirmation email. Visit Order Status to view tracking information. We apologize for the inconvenience.
Was your delivery originally scheduled for today? If so, the update to Saturday might be the later date Apple is referencing.