Did you know that the ABAP Keyword Documentation provides complete and up-to-date lists of repository objects that are classified as released API and can be used in restricted ABAP language versions? There is a list for each type of repository object, for example, CDS data definition or RAP behavior definition.
To access this list of released APIs, use the following link:
Released APIs.
Here’s how it looks like:

Released RAP behavior definitions

Released ABAP classes
The lists show all available released APIs for each object category. Object categories are, for example, ABAP class, DDIC domain, DDIC database table, and so on. The lists show the
release contract under which an object is released. They also shows the
ABAP language version in which the object can be accessed according to the rules of the release contract. The list is generated automatically, so it is complete and up-to-date. The column
State indicates the release state of the API - either
Released or
Deprecated. If an API has been deprecated, the successor object is listed in the column
Successor.
For more information about available ABAP language versions, release contracts, and released APIs, see the following topic:
ABAP Language Versions, Release Contracts and Released APIs.
Kudos go to my colleague
horst.keller, who has implemented this.
Further resources for released APIs: