Verifying that a blob is the original is the first step for censorship resistant media and distributed storage. If a server had to check with another server to know if a blob was the original it would never work.
While blossom doesn't have any p2p or specific censorship resistant tech in it. I think its "censorship resistant" enough. similar to how nostr events work with relays.

There isn't anything in the protocol saying events / blobs must be distributed. but because they can be easily verified, they can be copied to another relay / server without asking anyone.
This seems to lead to popular notes ( and maybe blobs ) magically distributing themself throughout the network. and so becoming "censorship resistant" enough 

 this makes a ton of sense. thanks for clarifying!