Hi Ninky,
The way I understand it, as long as you are not dealing with a rate lock, a rate change does not trigger a revised LE even if it makes the APR inaccurate. You would just reflect the accurate rate with the corresponding APR on the CD that you are delivering 3 days prior to consummation anyway. If, however, you have a rate lock agreement with the lower rate, than you would need to issue a revised LE within 3 days of the new lock agreement.
Hope this helps.