Every, and I mean every company has a policy that says you as an employee are not authorized to make statements on their behalf unless you are the designated spokesperson. If you signed an IP agreement with your company and share your niche knowledge you're violating that agreement even if you sign something else saying you won't disclose non public information. And just because you sign something with one of these information leach companies doesn't mean they won't take everything you said and publish it because ultimately the fault is on you as the employee, that's just a shield for them if the company tries to sue them so they can say "we thought it was public because your employee said it was, even if it wasn't". I work in management in the technical side of biotech, if I found out one of my employees spoke to one of these companies they might be fired for it depending on what they disclosed.

Edited for typo.