Perhaps.
> As they say 'Nature abhors a vacuum' - Once the diamondback moth numbers have declined significantly, another (probably more invasive) species will rise to take it's place.
Eventually, but evolution is slow. Why would the replacement be “probably” more invasive?
> The planet's ecosystem has had billions of years to balance itself out, who are we to assume we can do it better?
It’s not balanced. From one point of view, humans are a product of evolution and our errors are evolution’s errors, though even without counting humans other predator populations do sometimes wipe out their prey and then starve into their own extinction.
From a different perspective, we can do better because while evolution is limited to the gradient descent local minima of natural selection, we can do extreme long-term planning — which is how we’re even physically capable of having this conversation, let alone perform the genetic modifications that this article is talking about.