I addressed our wallpapers back in March.
https://forums.wincustomize.com/499091/
With online integration of WC into our apps, and even cooler things ahead, it is important for WC to have a strong wallpaper gallery (both animated and stills).
In the month before this project started (February), there were only 25 wallpaper uploads in that month, and 6 in January. Many of these were similar in styles. Nothing wrong with that, but that's not enough to be a competitive gallery with other apps that are doing similar things.
We needed to curate the gallery and that included bringing in wallpapers under allowable licenses. I will look at not trying to flood the galleries, but for right now we're not implementing any types of limits. The goal is a well-rounded wallpaper gallery, and everyone can help with that.