The Pixel 6 and Pixel 6 Pro will arrive with a day-one update

If you have ordered a Pixel 6 Pro or Pixel 6 Pro, it is important to know that you will need to take a little longer to get the phone set up. According to 9to5Google, there's a software update that you can install.
It is stated that you will need it in order to access all features. However, it is unclear what you would lose if you used the phone without the November security update. Google states that the build number for both phones is the same and should display SD1A.210817.036 for Verizon customers. The update may not be available if your phone arrives before the deadline.

Our team has confirmed that all review units have the same build after installing the day-one update. This means that any impressions you see are based on the same software. This is a good approach for a device that needs to be connected to the network. It allows production to ramp-up even while the launch software is being finalized.

After you have completed your device setup, the day-one update will be installed. Google claims it takes between 25 and 50 minutes to download and in the background install. The Pixel 6 and Pixel 6 Pro will be available for purchase starting October 28th. We have already reviewed both the phones and first-hand experiences with this update.