Hi guys, just to clarify this a bit:
Spark already has a built-in Wi-Fi antenna inside the camera body. So even without installing an external Wi-Fi antenna, the remote control function will still be usable once it is enabled by a future firmware update.
The Wi-Fi connector on the camera body is mainly there to boost/extend the Wi-Fi signal when you are using Spark from a longer distance. In that case, an external Wi-Fi antenna can be attached for better range.
So the external antenna is optional and would need to be purchased separately if you need stronger Wi-Fi performance over longer distances.