By default, any instances launched with the AL2023 AMI will require the use of IMDSv2-only The amount of users who are about to be shocked that curl http://169.254.169.254/latest/meta-data/ no longer works will be numerous. More on reddit.com

Just my musings from having built most these major OS with packer pipelines in the past, I have no affiliation to AWS or special knowledge. AL2022 was the successor to AL2 and had been under dev/testing for years. They just renamed it from AL2022 --> AL2023 a week or so ago. https://github.com/amazonlinux/amazon-linux-2023/pull/275 . I think they originally planned to GA in 2022, hence the name, and that slid out. putting out an OS is hard work. AL (1) was based off RHEL6 (red hat) AL2 was based off RHEL7 AL2023 is fedora based, so moving to more of a rolling release AL in general is derived off another OS and those OS end of life so Amazon shifts to something new which makes sense for supporting packages and such. So the way these fit in is the same as any new OS, RHEL or Ubuntu new releases. Even Windows server releases; 2012-->16-->19 etc. Traditionally, major OS revolve around a major kernel update as well which often made for breaking changes for COTs apps a client may be using. Support for AL and AL2 got extended out past initial EOL for sec updates, just guessing covid and/or getting AL2023 out the door all played in to those decisions. There hasn't in the past been a supported direct upgrade path from major AL releases, so you can't run an upgrade check and do some commands to update and existing server from AL-->AL2. Ive seen folks do that with RHEL. I've personally never been a fan in the past of in-place OS upgrades for linux or windows; so a rebuild by hand or the opportunity to put everything into Ansible or other conf was a fun adventure. More on reddit.com

Amazon should be backporting any security patches that are needed. No need to force an upgrade to a new version outside the scope of the distribution release. I’ve found that most tools just scan the version installed or being reported and can’t really tell if the security issue is present. There are places you can look to see what patches have been backported for example: https://alas.aws.amazon.com/alas2.html More on reddit.com

What I would highly recommend is building a docker container. Based on alpine if you can. This takes the host os completely out of the picture and paves the way to get it in to just running on fargate. It honestly isn’t that hard. AL 2023 is not designed to be a pet. It is designed to be cattle. Or an underlying infrastructure component that supports cattle. More on reddit.com