Conventional wisdom is that you acquire and hopefully perfect techniques before your body goes through serious growth spurts. Under the new system, you need a diverse set of techniques (and various jumps). So, you will need to look at how diverse/eclectic one's repertoire is and how well and accurately each technique is executed with consistency. That is the way to measure a junior skater's potential, especially for girls.
Under the old regime, achievements at junior worlds meant a lot in terms of projecting one's potential at the senior level. Under the CoP, they probably do not mean as much. At the junior level, they can do well on TES -- well enough to win competitions -- with a decent, not great, repertoire of jumps without technical accuracies and aesthetic (great skaters jump with great artistry). PCS at the junior level says even less.
So, to evaluate a young lady under the new system, you will have to pay more attention to each of her techniques and artistic disposition rather than her scores.
I have a high opinion of some Russian girls, most notably Tuktamysheva (not junior yet, I guess), while I am not as high on, say, Murakami because I see some significant differences in their jump techniques although their current scores may suggest otherwise.