He is not releasing visiond binary, the main part of the project though. Can't say with certainty buy I don't doubt it was a little of a publicity stunt
Nit: he did release the binary[0] he just didn't release its source, and there's a README that mentions this:
> Contact us if you'd like features added or support for your platform.
But I totally agree that it is pretty fishy to provide the source, especially in an "open-source" project...
[0] https://github.com/commaai/openpilot/blob/master/selfdrive/v...
[1] https://github.com/commaai/openpilot/tree/master/selfdrive/v...