Immutability is a matter of replication and not a matter of censorship. Once enough people have a copy any change will be known by all. There is decentralized enforcement of immutability after enough confirmations.
It is control over future transactions that is most vulnerable and centralized.
ahhhhhhhhh.....rrrrrrrreplicationnnnn...... ahhhhhhhhhh
BitLicense?
I would include changing transactions or changing the database after the fact (which also includes rolling back transactions) as a form of censorship.
If consensus allows these types of changes to occur, then some may view it as censorship.
But not absolute immutablity. There is always some uncertainty. It is not that people have copies, but that the witnesses have copies. As a person whom has a copy that is querying against the chain or making a transaction, I will only care about status of my account and the counter-party account. It does bother me somewhat when I hear of a witness not making a profit from witnessing though.