Apex domains cannot have CNAME records.
Question and response
Question
dig s3-deprecated.eu-west-1.amazonaws.com. NS
Answer
s3-deprecated.eu-west-1.amazonaws.com. 5 NS ns-994.awsdns-60.net.
s3-deprecated.eu-west-1.amazonaws.com. 5 NS ns-109.awsdns-13.com.
s3-deprecated.eu-west-1.amazonaws.com. 5 NS ns-2026.awsdns-61.co.uk.
s3-deprecated.eu-west-1.amazonaws.com. 5 NS ns-1476.awsdns-56.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0