A source over at XDA Developers shared a number of official preloaded wallpapers and videos for the Galaxy S20. The phone hasn't even been confirmed officially by Samsung yet. However, these wallpapers may tide Galaxy fans over until the likely official announcement in February.
https://www.notebookcheck.net/Download-the-Galaxy-S20-s-official-wallpapers-before-it-even-launches.450214.0.html