I don’t record video, so I have no opinion on whether a decision by canon in that space is reasonable. I do have an opinion about whether the motive you ascribe is likely. If prior non-Cine cameras offered it, then differentiation from the consumer and Cine lines should be put out to pasture.
Not at all. Canon went from class leading video features in their ILCs to class lagging. What happened in the mean time? They started selling Cinema cameras. We can clearly rule out a lack of technical ability as being responsible for the feature lagging since their Cinema cameras have the very features that are missing from their ILCs. They have been slow rolling video features into their ILCs ever since they started selling Cinema cameras. As to why they're only getting around to removing p24 now, it's not hard to explain. Their ILCs video capabilities were getting too close to the Cinema cameras in other picture quality metrics. They can no long cripple the footage in enough other ways to create market separation between the Cinema cameras and their ILCs. They can't get away with selling a camera with an extra crop in 4K anymore. They can't reply on bad rolling shutter now that they've had to improve the sensor readout speed. They can't rely on only shooting MJPEG or any of the other ways they've crippled video in the past. The old ways of crippling the video capabilities are no longer market viable so they've had to move to other methods of creating market separation. This is apparently the one they've settled on.
Canon wouldn't be doing this if they didn't think it was going to make them more money. p24 video is as close to free of a feature to implement on a camera that can already exceed that as there is. Yet, it is being removed from new cameras despite market demand for it. So, how does excluding a feature that effectively costs you no money to include make you more money when it will inevitably cost you some sales of the model it's been excluded from? The belief that doing so protects the sales of other more expensive and higher profit margin models and result in some upsells from people who must have the feature is the only explanation. Apparently someone did the math with highly flawed inputs/assumptions and concluded this was going to make them more profit.
For the umpteenth time, they are NOT removing p24 from their cameras. They are no longer offering 1080p24 in cameras that offer 2160p24.
For the umpteenth time, a lie repeated often enough does not become true, though you seem quite determined to disprove the maxim.
The 90D / M6 II don't do 2160p24. They don't do anything p24. It's been removed/excluded. The G7X III and G5X II don't do anything p24. It's been removed/excluded.
The EOS RP only has 2160p24 because it couldn't do 2160p30 [hardware limitation(s)] and it had to have 4K video on the feature list to be viable in the market. Otherwise it would be similarly missing 2160p24 like it is 1080p24.