Sucks for downtown's but I'm glad to see anything that leads to a broader distribution of population.
This. And I would say the broader distribution will actually be good for the environment as whole. Or at least it could be.
Downtown residents walk and use transit. Places with broader distribution of people typically rely on roads because transit isn’t economically efficient.
My intuition is that higher population densities are more environmentally efficient because more people can be served by any resource. Are you thinking otherwise?