Amazon recently alerted me about Google's initiative to require all certificates to be recorded in the certificate transparency logs. Looking at my current certificate for the website, it isn't currently set to be part of any certificate transparency logs until the renewal in 2019. You can check yourself by doing the following:
$ openssl s_client -showcerts -servername www.antonyjepson.co.uk -connect antonyjepson.co.uk:443 2>/dev/null | openssl x509 -inform pem -noout -text Certificate: Data: Version: 3 (0x2) Serial Number: 0b:1a:57:8f:1a:1b:56:90:b5:bd:6a:4d:67:07:8d:39 Signature Algorithm: sha256WithRSAEncryption Issuer: C=US, O=Amazon, OU=Server CA 1B, CN=Amazon Validity Not Before: Jan 3 00:00:00 2018 GMT Not After : Feb 3 12:00:00 2019 GMT Subject: CN=www.antonyjepson.co.uk [..snip..]
As it was issued before the cut off of April 2018. I'll do nothing for now and not opt out of Amazon's automatic inclusion in the CT logs upon renewal in February next year.