I think its cool that the market for kids is getting better but honestly what kid needs an AERO bike lol! Heck 99% of triathletes are set up in such a poor manner that their 'aero' bike is just losing them wattages due to the crazy seat angles that will have them with extra trashed legs when it comes time to run.
When I was 8, I got to learn to ride a bike. It was a rusty blue INDI 500 and I rode it till it literally failed at the head tube. Then I got a yellow one, it was heavy but strong and held up for years.
Last thing we need is 6 year olds asking for a new bike cos this years model is 12.5% laterally stiffer in the BB and 34 grams lighter due to hollow carbon tips in the rear stay..