the ping is just a handshake that does not communicate position information
Sort of, the Immersat ping, by analysis reveals the range from the satellite. That’s how the arc was determined, see the link.
Question: The transponder sends a signal that identifies the specific plane sending the signal, but what about these "pings" from the engine? Can they tell for certain they are from a specific plane, or could the pings be coming from any aircraft in that area?
Is it known why the connection was not established with the satellite? MH370 pinged, why didn’t satellite answer and establish a connection?
Maybe it did but because pilot had disabled ACARS there was no data to send.