Understanding most of these release notes requires an extremely deep understanding of WebKit and the relevant web standards.
I'd love to see projects invest more effort in expanding these out. Imagine how much more valuable this document would be if each of the bullet points (or just the most important bullet points) had a couple more sentences clarifying what it meant.
(This is one of the reasons I've started trying to publish annotated versions of the release notes for my own projects: https://simonwillison.net/tags/annotatedreleasenotes/ )