What Neuralink present appears to be almost the same as this semi-invasive from 2013:

https://journals.plos.org/plosone/article?id=10.1371/journal...

I am not up to speed on the non-invasive work, its called motion trajectory prediction (MTP) BCI. It is quite different from the method you decribed, which is a traditional motor imagey (MI) BCI.