When a company says it starts collecting data for the purpose of a and b then it is correct. Fine. However, the company very soon finds out that it can make more money out of the collected data when using it for purpose c and d.

I am sure the same will be done by the EU states in regards to upload filter. First, they use it in order to block data because there's a copyright in place, but very soon it's going to be blocked for other reasons (e.g. the user sends a message with a keyword the EU doesn't like etc.).