Wait, there's an official style guide?
(In all seriousness, I've been reading AWS launch posts for 20 years; this one was mainly imitating the S3 Files launch post but I diverged by adding the customer quote and the FAQ -- because of course I started this process with a PRFAQ, and some of the questions in the FAQ are legitimately important.)
I left 18 months ago, so my memory is a bit fuzzy, but there was at least an overall style guide, one for each post type (e.g. a launch announcement), and the style for procedures (inherited from AWS Docs).