In the headline, 'Microwave' stands synecdochally for 'microwave oven' and then also for the more-general category 'fast-heating appliance'.
When there are multiple ways to interpret something, assume the interpretation that credits the writer/speaker with some sense, not an interpretation that is most-literal or most-amenable as the setup for an insult.
But... don't discount the profound disappointment that a headline like that generates in those of us who do know how a microwave works. We were teased with the idea of learning something we thought would alter our understanding of the universe -- some sort of microwave version of the peltier effect[1] -- only to find out it was something as pedestrian as poetic license.
SCNR
"reverse microwave" is correct in a sense, because as gojomo pointed out, the author meant it as a way to convey the concept of "rapid-heating appliance".
"You can't do x because of thermodynamics" actually was incorrect, and didn't take into account multiple specific instances which show that closed systems can create such results.