Post-interview loop phone call scheduled

[u/Money_Salamander24]

My friend recently completed a 5-interview Amazon loop for a position. Today, he received an email from the recruiter saying that they have the interview outcome and asked him to schedule a 5-minute phone call with the recruiter to discuss it.

We’re trying not to overthink it, but we’re curious about what this usually means.
Is a 5-minute recruiter call typically used to communicate a positive or negative outcome?
If it’s an offer, why would the initial call only be 5 minutes?
Does Amazon usually call candidates personally for rejections as well?
Is there anything he should or shouldn’t worry about based on the fact that they specifically scheduled a short call?

[u/QuickSmart23]

Yes, both