Having witnesses to host IPFS servers is brilliant!

So far I have not seen a witness offering that (I have not been too much involved in steem it lately, though)

Other important thing is that DTube should inform creators on how to host their own content in their own IPFS nodes. That way, they have their own backup(s) and ensure their content is more available. Perhaps writing a guide that helps them set up a IPFS node and pin their content.