WSJ now reporting that the pings included "location, speed, and altitude.
This seems very odd. First there were pings simply to get the satellites' attention; now it's claimed the pings were sending significant data. Why would the system be designed that way? Where would it be getting the data from? And why didn't anyone seem to know that this capability existed? Wouldn't it be more logical for that data to be sent with the ACARS information rather than in an "are you there?" ping?
Possibly this is a mis-reporting of a claim that location, speed and altitude could be derived from the pings by various analytical techniques.