If traffic is transmitted by the transmitter the receiver receives from, then the traffic will be displayed on the iFly via the Radena SkyRadar. FAA currently has the traffic transmission configured to occur only when there is at least one airplane in the area transmitting its position via an on-board ADSB transceiver. When that happens, FAA transmits traffic information for all. BTW, the traffic info is for all traffic painted by radar in the area, not just traffic with ADSB transceivers.
The Radena SkyRadar is built to receive and send a display signal for weather and traffic. Bottom line: You can't be guaranteed ADSB traffic information (because your plane wouldn't have an ADSB transceiver). However, from reports I've read on VansAirForce.net, ADSB traffic is almost always transmitted by FAA (in the areas where FAA has the ADSB service working).
You can read about real world experience with ADSB traffic info by searching on ADSB on VansAirForce.net. Seems to be great.