It's still underground and will remain underground until accepted and promoted by the establishment.
They only have to say "this is not Aikido" and that's all. File and rank will follow.
The IP/Aiki proponents, if they are really interested in IP/Aiki spreading and becoming mainstream, should adopt a different marketing (for a lack of better word) strategy.
My teacher, who was a direct student of O'Sensei talked about the "secret" study groups that people partook in then. That still happens today. The manner in which a Shihan might teach at the headquarters might be very, very different from how he teaches at his own dojo. The "establishment" might not overtly promote the "other stuff", but they certainly haven't squashed it either. I am not waiting for a straight answer from some authority, rather trying to become as good, or potentially better than my teacher. IP/Aiki skills is one pathway toward that goal. I know my teacher is supporting me to become the best that I possibly can be.
Hopefully we all are on that path to self-betterment.