The MRE heater uses the same technology as the Heatermeal. The MRE heater releases hydrogen gas and lots of steam; not desirable characteristics in an enclosed space like an airliner.

I've never had or seen a heatermeal but I've had a few MREs. My guess is that activating an MRE heater might cause an alarm and possibly some quick and decisive action like and emergency landing!

Further, many of the troops know how to make a bomb or a reasonable facsimilie out of the heater!

Not a good idea for inflight meals IMHO.

Jim