IMO, blockchain human-readable naming generally creates a single coherent namespace and are thus "centralized" in terms of Zooko's Triangle. The singular authority is vested in shared consensus, but is singular authority nonetheless.
The real answer to Zooko's Triangle is to do human-meaningful name lookups as little as possible. For instance, in an ideal world I should be able to run a nameserver that stuffs all of ICANN's TLD pollution under an .icann label, such that I could type "blog.google.icann" to access what is currently called "blog.google". References to other resources would be specified with decentralized non-human-readable (ie cryptographic) identifiers, and outgoing links intended for human consumption would also have a relative hint so that my browser could turn the cryptographic identifier back into a human readable identifier in my own namespace.
The real answer to Zooko's Triangle is to do human-meaningful name lookups as little as possible. For instance, in an ideal world I should be able to run a nameserver that stuffs all of ICANN's TLD pollution under an .icann label, such that I could type "blog.google.icann" to access what is currently called "blog.google". References to other resources would be specified with decentralized non-human-readable (ie cryptographic) identifiers, and outgoing links intended for human consumption would also have a relative hint so that my browser could turn the cryptographic identifier back into a human readable identifier in my own namespace.