When using assets in rich text fields we couldn't detect them as "in use" in our media area filters.
But now instead we are doing that, so if you want to clear some space, deleting some unused assets from your media area, you are now good to go! The "in use" filter is now safer to use.
Last but not least, if you replace an asset we'll replace the URLs for you in all the rich text fields! This was sort of expected behaviour, but not implemented. Now it is and as a bonus we are doing it also on JSON fields, making also plugins that were saving assets in those fields more reliable.