Blocks are now supported in WP-Admin with full WYSIWYG and interactive preview. Here’s an example… using an old Mojomeja audio post from a while ago.
Here’s another… using a 360 photo…
When ‘bots’ for Facebook and Twitter detect the url to this post when shared, the plugin will add the media metadata for the first embedded Mojomeja block to be able show a preview ‘card’. (Your domain might need to be registered with them for ‘Twitter Card’ support. I don’t know if this still the case, but used to be for ‘player’ card support).
Audio and posts video post should be playable within Twitter on the desktop. (Facebook will link to the post from their preview)
Next up for development is to get the mobile app updated to support blocks (and whatever new updated methods and deprecations have been caused by mobile OS updates since I last worked on it!).
Previously (and with some of the earlier examples here) the embeds with handled by a custom WordPress ‘short code’.