[tor-relays] IPv6 Tor authority is down?

Hello, so to also enable IPv6 on my relay I followed the post-install article which said that one should ping all IPv6 authorities with the following command: "ping6 -c2 2001:858:2:2:aabb:0:563b:1526 && ping6 -c2 2620:13:4000:6000::1000:118 && ping6 -c2 2001:67c:289c::9 && ping6 -c2 2001:678:558:1000::244 && ping6 -c2 2607:8500:154::3 && ping6 -c2 2001:638:a000:4140::ffff:189 && echo OK.". This generally works fine except for 2607:8500:154::3, and further testing with an online tool confirms that the ping does not succeed. So I now wonder if I can simply ignore that and enable IPv6, or if this isn't recommended (and probably also what I could do in this case). Thanks a lot.