I think this article is really overplaying the amount of change gene editing can do post-embryonic/childhood development. The architecture of the brain is not encoded in genes, but develops as a result of genes interacting with the environment.
Genes encode things like neuronal growth regulation (e.g BNDF), receptors (e.g 5HT, OXTR) and transport of neurotransmitters (e.g DAT/SERT). We have bred mice that lack entire receptor systems -- they exhibit evolutionarily disadvantageous traits, but are fully viable [1].
Think of your brain as a city (an embryo at day 1 is an open plot of land where it will be built) and think of your genome as defining construction workers of different types. . The city develops as a result of constraints and feedback -- but once it is the size of say, New York City, it's not like gene editing can suddenly tear down central park and replace it with a football stadium.