Of course where richer people live there are more trees. People like trees. Trees are nice. Rich people can afford to live in nicer place than poor people. They can afford to waste space on nice trees instead of building cheap condos at the same place. It's all banalities, not worth writing at length about.
However, the last part of the article suggests that if you plant trees you could make bad neighborhood better. It looks like a wrong causality direction mistake. Rich people wear expensive clothes, but if you put expensive suit on a poor man, it wouldn't make him rich. Poorer cities won't be fixing by putting trees in them, this looks like a classic cargo cult thinking. It may make certain place a bit nicer, but won't change much.
However, the last part of the article suggests that if you plant trees you could make bad neighborhood better. It looks like a wrong causality direction mistake. Rich people wear expensive clothes, but if you put expensive suit on a poor man, it wouldn't make him rich. Poorer cities won't be fixing by putting trees in them, this looks like a classic cargo cult thinking. It may make certain place a bit nicer, but won't change much.