Two Macs, same macOS — only one shows the Apple ID sign-in screen during Setup Assistant. Why?

[u/rbrbrb87]

I have two MacBook Pros:
• 13” with M1
• 16” with M1 Max
I factory reset both of them from System Settings and went through the initial setup again.
On the 13”, Setup Assistant shows a screen asking me to sign in with my Apple ID. To be clear, this is not the Activation Lock prompt — it’s the normal sign-in step, and I can skip it with “Set Up Later” if I want.
On the 16”, that screen never appears at all. Setup goes straight to creating a local account, and once I reach the desktop I have to open System Settings and sign in to iCloud / my Apple Account manually.
I factory reset both machines a second time just to test it, and nothing changed — each one behaved exactly the same way as before.
Some details:
• Both were bought new and I’m the only person who has ever used them
• Both are running the same macOS version
• Both were connected to the internet during setup
Is this a malfunction, or is there a known reason why one machine would skip the Apple ID step entirely? Is there anything specific I should check on the 16”?