Well in Estonia (an EU state) this certainly doesn't happen with any regularity. The tax authority has the possibility to ask for bank statements, but they are required by law to inform the account holder of this check up. It only happens for cases where you're already under a tax authority investigation.
I know though that this is the case in more government-happy states like Denmark, where the banks send this data more liberally.
Anyway even if all the data would go automatically to the tax authority, that doesn't reveal anything. The company would be paying tax properly on all of this, that's the whole idea of laundering. To get the money into the legal system.
What happens when you limit the amount that can be made in a singular cash transaction, is that you then severely limit what businesses that you can use to launder it through.
If you can pay $100k in cash for a gold bar, it only takes 20 transactions to launder $2 mill. That's not all that suspicious.
With this new limit, you've now turned that into 200 transactions needed. Now the business stands out more because they tend to use business averages/data to spot things.
I know though that this is the case in more government-happy states like Denmark, where the banks send this data more liberally.
Anyway even if all the data would go automatically to the tax authority, that doesn't reveal anything. The company would be paying tax properly on all of this, that's the whole idea of laundering. To get the money into the legal system.