They should look at the success of other animated shows that tackled mature themes like both Avatar series, Adventure Time, Stephen Universe (to a lesser extent), My Little Pony FiM and others. Just because your target audience is a young demographic doesn't mean that the content has to be dumbed down for kids.
Hell, right out of the gate in season 1, My Little Pony tackled mental illness (
Party of One), Racism (
Bridle Gossip), and Peer Pressure and Stress (
Suited for Sucess)
I really hope CBS doesn't go the dumb down route. One of the things I like about the latest Trek is their willingness to take risks, and they should take some with this new series.