This is
against AA regulations.
You can use your cell phone, laptop and other electronic devices onboard until advised by the flight crew, but phone calls aren't allowed during flight.
An
older version of the site says more explicitly:
Cell phone and Voice-over Internet Protocol (VOIP) services are not available with inflight Wi-Fi.
I suspect you will have no real trouble listening to the call. If you participate in the call, it will be obvious to everyone around you (even in first) and to the flight attendants, who will tell you to end the call.
Either your meeting or your flight can wait.