I assumed that the triploid stocking was to augment the population without endangering the reproducing population. With that in mind I wondered if the population in the NFOW was considered low?
As for cutts I don't see any reason for them here. Yes they have a slightly different appearance, but they are still trout and in my experience seem to be small in streams, but they do have fast growing stillwater strains.
Trout are not native to Missouri, and as long as there is heavy river traffic, gigging, and warm water floods big trout just aren't going to happen in any numbers. There isn't an abnormal supply of 20" fish on the Deschutes in Oregon and you can't keep them or fish from a boat on that water. I realize they are a strain that evolved in warmer alkaline waters which doesn't describe the rivers flowing east from the Cascades, but big fish occur and they re therefore capable.