I don’t think a blockchain is necessarily the way to go here. We still want centralised powers (e.g. deleting racist references) and it’d also make editing references an absolute pain.
We could perhaps look into using some public-key cryptography (the bit used in blockchains to verify accounts making the transactions). Data would be stored centrally still, but users who downloaded their data would be able to have it authenticated whether we stored it or not (all we need is the relevant public keys to check), making it easier for these kinds of data re-uploads