Here are the refs to EF lenses you missed in the thread, which had very few participants:
What I have found is on some larger zooms that if you remove the lens from the body while power is on, you can get a rattle. SO turn off the camera before removing the lens.
My EF 100 L Macro sounds terrible, as do other examples of the lens that I've checked (four or five) but the ability to make noise does NOT effect its ability to make images...
Exactly!! The 100 Macro is scary sounding. I have detached it without turning the camera off while the IS is still whirling. That even makes things more loose and rattly. If you let IS come to a stop things get a little more solid sounding, but I thought it was broken when I first got it. One noisy lens.
They are all for EF lenses that rattle. I have the 100-500mm - it wobbles but doesn't rattle.
Okay, I thought you meant there were people specifically responding with comments about the EF 70-200 mm. I did see those EF 100 mm remarks, but I don't think they are meaningful to the question at hand: Is it normal for the RF 70-200 mm IS unit not to park regardless of the way power was cut from it.
I am under the impression that this is the case. And that Canon intends it to be this way, based on all the discussions that took place about this with happening with the RF 100-500.
A rattling sound is of course not the same thing as a wobble of the IS elements itself. But how noticeable such a sound is would depend both on how far away your ear is and how hard the lens is shaken. Hard to compare aspects. I would think that unless movement while being turned off is physically restricted, there has to be a sound when the lens is moved abruptly as the elements hit the lens sections. Even if it is barely noticeable, especially under regular circumstances.
It also seems to me like the comments made by the Canon service person quoted by the OP are misguided, since it seems like they talk about noises made by the IS unit while it is powered on. Whoch is not what the OP asked about.