It's not a Mind-Machine Interface; it's a Brain-Machine Interface.
If you're a physicalist, then there is no such thing as a Mind-Machine Interface, because there are no minds, only brains.
If you're a dualist, then the technological goal described in the article is no more a Mind-Machine Interface than the laptop on which I'm typing this comment. In both cases, the brain mediates between the mind and the machine -- the only difference is the presence or absence of additional mediators (fingers, a keyboard, etc.).
The term "Mind-Machine Interface" is either misleading, or it unnecessarily takes a side in the physicalism vs. dualism debate (by implying that "mind" is just another word for "brain"). "Brain-Machine Interface", by contrast, is a term that both philosophical positions agree is accurate.