Was Microsoft employee. Did not worry one bit about talking to a recruiter on LinkedIn. Your immediate management is unable to see or even get that data. You would have to trip an alarm elsewhere, trigger a major investigation, get legal sign-off and then maybe Microsoft would ask LinkedIn to pull that data. Even though MS owns LinkedIn, they are treated as a separate business entity. LinkedIn has its own security team etc.

Even MS's own recruiters will use LinkedIn to contact current MS employees for internal positions.

Tech is a double sided coin. Things like this have the power to be abused, even easily at times, but that doesn't mean they always will be.