That tagging scheme would have to do more with connectivity than end-of-freeway expressway tagging. Typically trunk has been used to classify those little sections of motorways through signalized interchanges to connect the ramps on the non-freeway side with the freeway (in this case, the southbound 215 ramps with Summerlin Pkwy), though this would imply that Summerlin Parkway would be a trunk road if not a motorway, but since it primarily only serves local traffic rather then through traffic like I 11/Route 95 or bypassing traffic like the 215, primary for that little segment makes sense to me. AFAIK many other mappers would probably disagree with that conclusion since motorway renders at the same level as trunk and is thus often considered at the same importance level. However, if motorways are being classified based on physical characteristics rather than importance, Summerlin Pkwy, the motorway spur of the 93 Bus. loop in Boulder City, and the Airport Connector should be treated as freeway-standard primary roads and the 215, 11/95, and I 15 should be treated as freeway trunk roads, meaning your change to that segment of Summerlin Pkwy should be correct.