10.3-RELEASE is a new version, yes. (It was released last week, but it took a week to get the new version into the AWS Marketplace. I'm still working out the kinks in the process.)
The "since 06/06/2014" is for FreeBSD 10; there's a separate Marketplace listing for FreeBSD 9, which shows "Available on AWS Marketplace Since: 11/20/2012": https://aws.amazon.com/marketplace/pp/B00AA25MLK
The "since 06/06/2014" is for FreeBSD 10; there's a separate Marketplace listing for FreeBSD 9, which shows "Available on AWS Marketplace Since: 11/20/2012": https://aws.amazon.com/marketplace/pp/B00AA25MLK