Nitpick: there are third party lenses for the RF mount but they are all manual focus. As you stated Canon has not opened up the spec and so third parties have been unable or unwilling to violate the patents that would allow them to make use of the RF electronics required for auto-focus.
I real shame as I would love to use some of Sigma glass on there without use of the EF adapter.
I real shame as I would love to use some of Sigma glass on there without use of the EF adapter.