I've personally tried to do use a tablet in a productive way for the child, and it's all about the apps rather than the tablet itself. Tablets for children (Android knockoffs, essentially) provide what's needed, that is, account controls.

Problem is: there is a limited amount of apps that are genuinely fun and educative. If Amazon wanted really to do something truly educative for children, they'd build a whole market for it, the marketese I see in the article doesn't support that.