No, Microphone.setUseEchoSuppression does nothing. It is just a placeholder function that Adobe planned to implement at some point.
As of December 17, 2015, Adobe has not addressed AEC for AIR on mobile devices, on both Apple and Android platforms.
However, a contact of mine talked with Chris Campbell at Adobe a couple of times regarding AEC for AIR Mobile, and Chris said they had cleared legal WRT licensing, and was pitching AEC for inclusion in AIR 20 (December 2015).
I haven't seen any other indications that Adobe is going to do this or not. I know it would be a tremendous enabler for developers of video chat-based apps, to include support for mobile devices. We have AEC on web, and desktop AIR. Just need mobile to create omni-channel video solutions.