RFC 5855 “Nameservers for IPv4 and IPv6 Reverse Zones” specifies a dedicated and stable set of nameserver names for each of the IN-ADDR.ARPA and IP6.ARPA zones.
The secure and stable hosting of the IN-ADDR.ARPA and IP6.ARPA zones is critical to the operation of the Internet, since many applications rely upon timely responses to reverse lookups to be able to operate normally.