No. Just plain no.
If you have a prep-op track and a JO track, I really think that should be sufficient. The kids/parents who don't want to commit to the hours, commitment, and money that is required in USAG can take the prep-op route. The kids who are dedicated and push their way through the USAG route at their own pace. Picking and choosing who goes into an "A" group or "B" group is nothing but damaging to any of the kids.
I've written about my personal experience with this before but I will write about it again. I switched gyms as an 11 year old level 5. The HC did not see me do one skill, based on my age, level, and size he immediately put me in the "B" group. I didn't get the same coaching or opportunities as the other kids and it was miserable. I had no idea what I did wrong to be put in that group, and as someone who wanted nothing more than to be the best I could be in the gym, it was deeply hurtful to me. I still feel angry boiling over when I think about what this gym did to children and the impact it had on me, not only in terms of my gymnastics skills and ultimate progression, but also on the way I felt about myself as a person.
All kids deserve the OPPORTUNITY to progress. Not all kids will take advantage of that opportunity, not all kids will be capable of reaching the optional levels, but they should at the very least be given the chance if they have the desire to work hard and improve and have a passion for gymnastics. Some kids will look like they have limited potential early on and surprise you, others will look like future elites only to see their rapid progress screech to a halt when they grow or face a mental block.
Things like lack of commitment, unwillingness to commit to the required hours of the USAG program, and similar problems can, and should be addressed- and maybe in those cases the prep. op track could be recommended as a better fit. But in no way should a child be pushed onto a "B" team for body type, age, or because they are a TOPs superstar.
Just my 2 cents for what it's worth.