Sorry Harry, you're completely barking mad on this.===
I highly doubt Canon itself will make an RF to EF adapter...BUT... I do think someone like Wooden Camera might sell one as a package along with one of their Camera Cages and/or other accessories. In terms of focus and iris, they could put a control ring into the adapter itself for semi-automatic and full-automatic focus and iris control protocols which already have been reverse engineered from a technical point of view by Sigma and others.
If you are desperately trying to hold onto the dream that some day maybe you'll be able to use the glorious RF glass on an EF body then by all means continue to delude yourself.
It won't happen. Canon would never do it. They want to transition everyone over to RF as soon as possible.
Wooden Camera? They almost certainly haven't got the experience to reverse engineer the RF protocol.
Sigma? They almost certainly haven't reverse engineered the RF protocol yet. Remember it took them DECADES to get the EF mount right (something that Tamron still haven't 100% figured out with some of their lenses not working on the adapted R, and they couldn't even get the EF-M protocols right).
The RF protocol is far more complex than EF. For all we know it may require signed authentication between lens and body, and/or have an encrypted communication channel.
The only way you'll ever be able to adapt an RF lens to work on an EF camera is if you stick an EOS R on the hotshoe.