No actual blockchain will be able to (even in theory) take down DMCA'd data. There is no mechanism whatsoever for complying with such requests, anymore than there's a mechanism for reversing transactions associated with activity a government deems illegal.

Individuals running IPFS gateways or nodes may be directly targeted and asked to take down data, but there's no mechanism for "the network as a whole" to remove data. It's exactly the same as bittorrent. So long as one individual in some hard-to-reach jurisdiction continues hosting the data, nothing can be done.