My thoughts: largely pointless. Microwaves/magnetrons resonate/vibrate the molecular bonds within water to generate heat. Very similar to applying heat to water in order to boil it, which you’re going to do anyway when brewing a coffee. Coffee beans are already roasted to bring out the aroma so why try to repeat this step by targeting the little water left in each roasted bean, whilst also running the risk of overheating the beans — microwaves are directional and can heat unevenly, creating hotspots (hence the rotating plate) — and thus breaking down the very chemical compounds that produce the aroma in the first place. Furthermore, the beans are then mechanically ground, which also releases the aromas, and it’s important not to generate heat during that step too. Conclusion: waste of electricity that introduces an extra heating step that could actually ruin the flavour.