Some languages like Python refer to their anonymous functions as lambdas.
"Cloud functions" (ala GCP) would be more explicit, but the reference is a sensible one.
Doesn't mean they didn't choose that very carefully and on purpose.
> Identity management, also known as identity and access management (IAM)
While it might be an 'industry wide acronym' and it might make sense for people with experience  it is not immediately apparent to certain people who would like to try AWS or who aren't doing these things for a living.
Things should be labeled easily for the lowest common denominator. If you want to use an acronym it should appear after the full name of the item.
Not this: IAM
But this: Identity and Access Management (IAM). And the full description should appear everywhere. Not just in one place (like in a legal contract or the beginning of Jeff Barrs blog post) but everywhere.
Why not? Why not do everything to make it easier. It's not like we are talking a printed piece where space matters. People reading on mobile? So what still spell it out. There are always new users who don't know the jargon.
And if you want to have an express page then take the verbose page and make an express page from it for people who don't want it spelled out.
 Just like people with experience know what a MAC address is vs. a Mac Computer
I definitely try to do this in my blog posts, but I do assume that my readers have been following along for some time, and that they have internalized some of names.
As you noticed, I like to use the full ("formal") name at the start of each post, and then switch to the informal name after that. In fact, I have a shortcode system that makes this fairly easy. The first reference spells out the entire name and is linked; the others use a short name and are not linked.
AWS is a technical product, it's not Wordpress or Mailchimp. Just like Cadence makes EDA products and MATLAB makes maths software, AWS makes datacenter computing available on the cloud. It's not aimed at users who have a few minutes of experience with some Lubuntu desktops at home.