Unless you are on JFK I wouldn't assume any aircraft assignment beyond the next week or so would hold. Even within a week the aircraft switching is pretty full on. But that apart, you may be better off in WTP, as you point out the old CW had some advantages, not least the seats you identified were often unpopular with other travellers so you were more likely to get them. See also this recent thread:
One parent, two 6 yo kids in CW, where to seat