In AUR are maintained/available for example 
https://aur.archlinux.org/packages/ubuntu-wallpapers
Other samples with NON ARCH LINUX contents (themes, forks, icons, wallpapers, tools). 
antergos
https://aur.archlinux.org/packages/?O=0&SeB=nd&K=antergos&outdated=&SB=n&SO=a&PP=50&do_Search=Szukaj
ubuntu
https://aur.archlinux.org/packages/?O=0&SeB=nd&K=ubuntu&outdated=&SB=n&SO=a&PP=50&do_Search=Szukaj
manjaro
https://aur.archlinux.org/packages/?O=0&SeB=nd&K=manjaro&outdated=&SB=n&SO=a&PP=50&do_Search=Szukaj
suse
https://aur.archlinux.org/packages/?O=0&SeB=nd&K=suse&outdated=&SB=n&SO=a&PP=50&do_Search=Szukaj
fedora
https://aur.archlinux.org/packages/?O=0&SeB=nd&K=fedora&outdated=&SB=n&SO=a&PP=50&do_Search=Szukaj

Please save manjaro-material-blue-wallpaper-git package. Regards