For functions added in a release you could search for "Introduced In" followed by the release number and get a close approximation. See for example the search for release R2022a.
For functions updated in a release we don't publish a list. I suppose you could do a file comparison between each of the files in an installation of the previous release and the new release, but likely much of what you'd find would be minor changes like typo fixes or clarification to help text. And that wouldn't help you detect changes to the code of a built-in function that did not require any changes to that built-in function's help text.
What were you hoping to do with such a list? I can think of a couple reasons why you might be interested in that list; I'd like to know what reason you had in mind.
