Main reason why most people prefer tumbling is privacy and not because of getting blacklisted for using gambling sites which in case only Coinbase does this kind of behavior.

In your article you mentioned about coinjoin which is not effective anymore due to the fact that you will be traced back to your main address by reverse engineering process.
Nowadays what people prefer is to mix coins via already available trusted tumbling services like Bitmixer. They have a large reserve of coins and you will be able to tumble your tainted coins easily.