There does some to be some confusion. What is being discussed is traffic avoidance. None of these systems provide any instruction beyond placing aircraft position (accurate or estimated) on a display followed by a verbal warning if any may be likely to cause a conflict (that's how the garmin works anyway).
The similarity to TCAS is that aircraft will interrogate other transponders for information rather than passively listening in to responses from transponders to SSR.
It is an informational tool to help provide better awareness, nothing more.