AMA: Enrolling modern devices with Windows Autopilot

As Danny mentioned, this is a 2 part question and there isn't a simplistic answer.

1) Where is the update scan coming from? ConfigMgr/WSUS or Windows Update for Business?

WUfB policies can be configured from Intune, ConfigMgr, or GPO/registry keys.  ConfigMgr will use the Software Update Point, but dual-scan can be allowed so the answer can be both.

2) Where is the update content coming from?

ConfigMgr can allow clients to use Microsoft Update for content missing from distribution points or force the traffic to be within the network (Distribution Points and P2P).

WUfB (Delivery Optimization) will utilize Microsoft Update for content but can also use P2P and the Microsoft Connected Cache (DO in-network cache).

If you want to get really specific with a scenario, please post comment with as much detail as possible.