We have previously imported from the stable branch, but [9963] reverted back to the trunk branch.
See #5266 & #5020 for the limited history I have.
I suspect that reverting to using the stable version would cause the same confusion again, without extra effort being put into creating versioned handbooks.
If the Editor team would like to confirm the direction, a PR can be opened against https://github.com/WordPress/wporg-developer/blob/1c40953d68c3554499859d61bbbb859870fb5ffa/source/wp-content/themes/wporg-developer-2023/inc/import-block-editor.php#L8