Oh no, just got one similar to OP’s but the MFC series with extra copy/scan features after a great experience with the old equivalent Brother model I had for about 20 years with near zero problems!
I realized the new model was surprisingly cheap and with features I always wanted on the old one (which was now starting to show its age in a few ways), so I made the upgrade. Hope I won’t regret it.
I can imagine this being initially an accidental discovery like oh every time so and so’s body interacts with the WiFi signal it’s the same pattern… until someone starts exploring this further… and then some engineer or their manager started looking for applications for this. In my experience engineering researchers especially are very good with coming up with use cases for whatever tech they’re working with, with little ethical consideration.