You're close but the idea gets much broader and extends to augmented intelligence as well.

Once the brain is readable, it actually becomes easier to justify legal protections for augmented compute intelligence, ironically enough.

The inevitable end result for a benevolent manifested planet / universe is we all have equal share of impenetrable compute.

This result is unavoidable if we want to live a free and prosperous life.

It requires encoding certain human rights, freedoms, privacy protections, and corporate / government limitations that human beings are not remotely ready to encode yet.

So by extension, I won't hold my breath on brain scanning being a technology I would be comfortable with in the hands of this current world and thinking.