I have built and deployed a WebSub Hub bridge for IPFS (well, more for IPNS/dnslink, since pings when raw IPFS content changes… well… it doesn’t 
)
One cool outcome of this is that anyone on neocities or another IPFS+dnslink-enabled publishing platform can add a couple lines to their Atom feed and be instantly followable by Mastodon, GNU Social, Friendica, IndieWeb Readers, etc. (Updates from neocities may take a few days to publish, though, since they don’t add to IPFS instantly).