itch.io

Is there any place which lists the differences between the Reborn packs and the original packs (for this Castle pack and the others, such as Dungeon, Grasslands, etc)?

The license says "These assets were created for the design of video games, but can also have other uses (video editing, banners, etc. ...)".   If you're going to limit those "other uses" to a specific list, then you need to specify EXACTLY what is allowed.  As it is right now, the license is too vague.