SEC Rule 21F-17(a) prohibits any “person” from taking “any action to impede an individual from communicating directly with the [SEC] staff about a possible securities law violation. Rule 21F-17(a) protects not only whistleblowing employees, but investors as well.
Source: https://www.forbes.com/sites/insider/2021/07/27/investors-are-entitled-to-whistleblower-protection-from-the-sec/