I'm with White Knight on this. Click, you're talking nonsense.
You contradict yourself when you say,
Quote.
"that if the current procedures in the FCOM are followed, then there SHOULD be no problems."
Is there any aircraft of which the same isn't true?
The ATR has probably been tested more in icing conditions than any other aircraft in it's class.
Politics? Yes. There's nothing the American aircraft industry would have liked more than to have banned this 'foreign' aircraft from operating in the US.