Haha, a few years back I remember joking on here saying that even Leica would have IBIS before Canon.
But the thing is looking at the new RF lenses it seems only the 1.2 primes and the exotic 28-70/2 don't have IS - the 2.8 wide angle zoom has IS, the 35mm 1.8 prime has IS, the 24-70 2.8 has IS, the 24-105/4 has IS, the 24-240 has IS... So really I am no longer bothered, especially as the 15-35 and 24-70 have IS. I assume upcoming 1.8 primes will all get IS and the f/4 zooms already had it in EF mount.
It would be nice for some adapted older glass to get the IBIS but I can't see Canon factoring that into their decisions. I would love it for some of the my EF glass but I'm not holding my breath now. Indeed if they brought out a body with IBIS I think half the sales of the new RF 24-70 would be lost to the equally sharp but much cheaper EF 24-70L II.
I think now the question will be quite simple for Canon. Does the combination of IBIS with IS offer a real world difference for the photographer? If not it wouldn't surprise me if they don't bother with IBIS for many years to come. Most professional uses of the 1.2 primes simply won't rely on IBIS, no wedding photographer is going to say to the bride "sorry the photo is blurry, I was trying to see if I could get the shot at 1/15 and ISO 100 to satisfy an argument on an internet forum!" - they are already putting their shutter speed well beyond the minimum for safety.
So this is what I think Canon is up to........
They have basically identified three main markets for the RF system.
1. The professionals: For this group, they created the exotic lenses without IBIS. We are talking RF 50 f/1.2, 85 f/1.2 28-70 f/2 and the likes of 16-28 f/2 or even 70-135 f2 to follow. If you notice, all these lenses does not have IS. I asked myself why, apart from maybe size and price, I believe the major reason is because Canon is working on Pro bodies that will have IBIS to go with these lenses. They know that this lenses would be bought mostly by professionals and they are getting the camera ready.
2. The Prosumer: For this group, they have the current RF f/2.8 trinity with IS. These are for those who will only stay in the $2000-2500 range camera and thus the EOS R is adequate for. Of course this group will always reach a little up into the Professional area sometimes especially for better glass. The portrait, event and even landscape folks with be happy here. This group also may utilize lenses from the Consumer line sometimes.
3. The consumer. These are the group that want a decent camera and lens with IS. That is why the cheaper RF lenses like the RF 35, and RF 24-105 have IS. The IS mostly is needed to help this group have better shots without getting technical.
I however believe that with time, when Canon finally master making IS and IBIS work together flawlessly, all levels of camera will have IBIS.
This was my reasoning when I pre-ordered all the new f/2.8 lenses. I knew that in 2020, Canon will come out with a 5DSR like mirrorless with IBIS and another set of none IS f/2 lenses to complete the f/2 trinity. However I also know that the best camera and lens is what you have right now.
For my needs, I will love a higher resolution camera than the EOS R, but the EOS R does what I need right now better that my 5D Mark IV.