I didn't really get into IT until 93 or so, then quit immediately to move to Cal and do some design school stuff, so my knowledge of things from that era is shaky and anecdotal at best. But, IIRC, the standard MO was to put cars in ITS (or aclass higher than where they should really go) for a bit to see how they did, then move them to where they really belonged. So the 1st gen RX-7 was in ITS, and I seem to recall it got moved to ITA in the early 90s, which spurred my interest, as I though it might be able to run with the then top dog RX-3SP, but didn't stand a chance against the ITS cars.
Point being, I think that the CRB often put cars in a class higher and watched it shake out. And sometimes, I think they "forgot" about cars, or didn't have enough data (how could they, LOL) or a good enough feel to move them, which helps explain how some cars ended up places they clearly didn't belong.
So, while some subscribe to the belief that IT has never been about "comp adjustments" or moving cars between classes, it doesn't ring entirely true to me.