I have now seen the video of the Canon EOS R6 IBIS in action, and it looks really smooth. The EOS R6 also appears to use the same type of grip as the Canon EOS RP.
Other things that I noticed from the video, the EOS R5 will be magnesium alloy, but the EOS R6 will not be. There is also no top-down LCD on the EOS R6, but there are multiple scroll wheels and I'm not sure what that's about. The camera also has a much more rounded shape than the current EOS R cameras.
For the record, the source that sent us the image and video of the Canon EOS R6 has requested that it not be published, and we will always respect those requests. I usually see cameras well before they appear elsewhere and I want to have that continue, so I will not burn any bridges for some extra clicks.
The EOS R6 is real and has glorious IBIS, that's really all we needed to know!