That has been possible without brain surgery for decades. This was literally a demonstration by undergrad students when I was visiting a university in 2011 or so. They used one of those "shower caps" you place on your head to sense brain waves.
(Ignoring that the Neuralink device has many different capabilities, including and especially being able to cause brain stimulus, which an EEG cap cannot. And that writing data into the brain is a major component of what I said.)
It terrifies me that a multi-billionaire is more disillusioned about this technology, than a BS-student.