Personally, all of what you wrote is a benefit when it comes to release notes. I don't want flashy GIFs, words written by non-programmers who don't actually understand what they are writing and I definitely don't want the marketing/web design part of a company to be involved in it.
Simple, tell me what changes, where I can read more and that's it. It's the perfect release notes.
But, as always, people like different things, as is apparent here :)
I just want important information boiled down to code examples and lists of features for me. I don't need to read an essay on the history of string interpolation
An example can summarize hundreds of words with less explanation cruft and wording confusion.
Of all the math classes I've taken, the best teachers are the ones that just walk through examples. Not the ones explaining in abstract how to solve problems generally.
Simple, tell me what changes, where I can read more and that's it. It's the perfect release notes.
But, as always, people like different things, as is apparent here :)