TL;DR: I don't really know.
My health care insurance does this too. I save some $50/yr to agree to a call from an RN to help me with my health condition(s). A coworker who formerly worked in health insurance told me that while they also help you to navigate the health insurance system and/or find cheaper care or whatever, you're actully still talking to your health insurance company and not your doctor and so anything that you say is now on your health insurance record. This can be used to deny future coverage for an existing condition, dissuade you from pursuing more expensive (for them) medical treatments or to raise your company's rates for certain ailments (for example, everyone at your company smokes, they'll drop coverage for asthma).
The health insurance company doesn't know all of your ailments simply based on the billing codes. You are protected by HIPPA. Your health insurance company can ask you anything and anything you say to them is not necessarily covered by HIPPA.