I propose holding off reaching conclusions of performance differences (and castigating the source for a display of incredible stupidity) until we have actually done some on-track comparisons. The comparison of these two generations of wheels seems similar to the comparison when the last major mold change happened... which I think turned out to be "a wash," i.e. the positive changes were almost exactly offset by the negative changes.
In each case, the new generation of wheels introduces some positive performance changes and some negative changes. In combination (and on a "standard Cub Scout track") we might just see another "wash."
What I do see in this newest generation is a reduction in the potential for builders to improve performance by extreme wheel makeovers. The "fundamentals" are still available ... truing, balancing, lubricating, polishing, but there is less to be gained from inertia reduction.
I asked a question earlier about "why" the nail length was shortened. My thought process was that if shortening makes use of a lathe more difficult but does not affect the use of a hand drill, then axle processing is pushed back toward BSA's concept of what a Cub Scout is expected to be able to do.
Maybe, just maybe, BSA is "dumb like a fox." It wouldn't be the first time!