These coinjoin protocols relay on a non-standard feature that should not be relied on.
They need to modify their coinjoin protocol to adjust to a more standard definition of the bitcoin protocol.
It is not Ocean's fault. It is nobody's fault, just a misunderstanding.
I think what knox did was show the issues of having diverging bitcoin clients. People are building their protocols on default network policy that might be different between mempools. This is more of an unexpected side effect than targeted censorship. It also shows that decentralization is hard and having multiple competing clients would expose many issues like this.
