As I understand it there are many detailed patents that never get produced so I think we have to wait and see.
I like IBIS and wish Canon had it. To have IBIS with a 1.2 or 1.4 lens is fun. However I wouldn't be shocked if it isn't a priority for Canon.
Canon tends to concentrate on two key markets. One in consumers and the other is professionals. IBIS is of little interest to either. Consumer lenses all have IS. And now with the upcoming RF holy trinity the key pro lenses will have IS.
Who does this leave? Advanced amateurs - probably the majority who post online. We make a lot of noise but are fairly small in number. Nonetheless we are a market that clearly Nikon and Sony has gone after but we simply aren't the priority for Canon and frankly I don't mind that - I think it's the reason Canon pays so much attention to things like ergonomics, build quality, menu systems, colour science, auto focus etc rather than obsessing over dynamic range at crazy ISO.
So for the serious amateur IBIS can be very nice. It can open up some creative opportunities, it can keep ISO low for landscapes without a tripod, it acts as a sort of safety buffer if shooting say a 135 or 85 and using shutter speeds of around 1/60 or 1/100.
The thing is most professionals won't take those risks anyway. They can't say to the new bride "I'm sorry the moment he gave you the ring has a blurry photo, you must understand I was trying to shoot it at 1/20 so I could use ISO 100 and brag online about it". And most f/1.2 lenses are being used for things like portraiture where professionals will control lighting anyway.
So while ever my first instinct is to say I want IBIS, I am pleased if it comes, it doesn't shock me one bit if Canon decides to continue with just in lens stabilisation and decide that f/1.2 lenses aren't being used in a way that benefits from IBIS. I suspect we will get an answer when we get some slower aperture primes for the RF mount. If we get more 1.8 primes like the 35mm with IS then IBIS would really only be for the 1.2 lenses and who knows if that's viable.