My prediction: very powerful, non-invasive, wearable BCIs will be revealed -- in months to a year. The tech already exists; what is uncertain is exactly when groups will find it prudent to share what they have created. There are several issues in play:
* If the tech is revealed, other groups will immediately try to make their own -- perceived risk of failure will be lower. It's therefore prudent to find a way to keep it hidden as long as possible, while making money from it.
* What if a country like China uses it on various classes of workers?
* Best to wait until there is some nice show-and-tell stuff -- e.g. a typing-by-thought app that really works, really fast.
Sounds cool, but this can't go on the timeline yet. There are no published sources, papers, or articles of these next-gen BCIs. Nothing that can be cited.