You can test this claim directly against a AWS S3 bucket.

First 100KB of a 100GB+ file:

curl -H "Range: bytes=0-100000" https://overturemaps-tiles-us-west-2-beta.s3.amazonaws.com/2... --output tmp -w "%{time_total}"

First 100KB at the 100GB mark:

curl -H "Range: bytes=100000000000-100000100000" https://overturemaps-tiles-us-west-2-beta.s3.amazonaws.com/2... --output tmp -w "%{time_total}"