Yes mines said it a number of times
Good thought but think about this:
The computer 'KNOWS' the IAC is closed on startup
It pulses it 10 to open it how far it thinks it needs for 1000rpm
It gets say 1700rpm says "oh sheit" and closes it some
1600rpm, closes more
1500rpm, its taken those 10 pulses back and 'KNOWS' its closed
computer: "Ahh dumb driver must have his foot on the pedal" or "oh damn there'* a hole in the (dirty) throttle body" or any number of other 'excuses.'
Now the adaptive part would be if it can figure out that those aren't the problem and figure out that the IAC isn't all the way closed. BUT the computer needs to make assumptions based on what it 'knows' and if it 'knows' the IAC is closed it won't question it. I think it'll just assume its a problem elsewhere.
I think this is somewhat proven by any rough or high idle caused by any air leak other than the IAC. If you drill a small hold in the TB valve the PCM COULD close the IAC more to compensate but it probably won't, it'll just sit confused on whats going on. Same thing with dirty TB'* causing a rough idle, the IAC could, in theory, compensate but it doesn't. Whats your thoughts?