Odds are you will still be in the Cascades section just not necessarily 2340. Perhaps the resort can tell you what unit you will be in if you call a few hours in advance.
According to my resort map from last year, if you want to avoid the noise from State Road 535 then cross your fingers you do not get booked into the following Cascades units 2537 to 2577 and 2666 to 2701 because these two buildings face the highway. Despite the large barrier wall surrounding the resort on the highway side, when the 535 is busy the noise can be a bit of an issue for some people. From most areas within the resort you would never know there is a highway out there!