diabonas [1] filed a deletion request for iptables-nftables-git [2]: The sources for building this package do not exist any more, see PRQ#17332 (https://lists.archlinux.org/pipermail/aur- requests/2020-January/036418.html) for the deletion request of the stable iptables-nftables package. Also confirmed by this comment:

jaxxed commented on 2014-10-19 10:55 "iptables over nftables tree (OBSOLETE, use iptables tree)" (http://git.netfilter.org/iptables-nftables)

[1] https://aur.archlinux.org/account/diabonas/ [2] https://aur.archlinux.org/pkgbase/iptables-nftables-git/