Yes, that's what I'm saying. It doesn't matter if you can turn IBIS on or off. It's not the functioning of the IBIS that's generating the heat. It's not even a matter of more heat generation with IBIS, it's a matter of dissipating the amount of heat that any sensor generates.
If the sensor is capable of IBIS, that means the sensor and all of the hardware that dissipates heat from it now must be part of that assembly that moves as part of the IBIS. If you have a sensor that's firmly mounted in the camera, you can attach all the heat dissipation hardware to it that you want. Your only limitation is space within the camera and the weight of the camera itself.
As far as the argument that they don't want to have IBIS so that they can sell more lenses, I think that's some serious tinfoil hat thinking.