HR functions like the lowest level of police forces within a polity, they're there just to snitch on you to their superiors (next level up law enforcement within the corporation) or deal with you directly whether in fines, suspension or exile.

So, yeah I wouldn't trust HR with these matters and it seems to me that Bezos is only interested in cover-ups when he recommended this course of action out of fear that employees may seek friends in the press to expose those practices from now on undermining his plans of non stop exploitation at his sweatshop.