>Eventually, but evolution is slow. Why would the replacement be “probably” more invasive?

You don't have to wait for the evolution. There were already cases when a species from other country/continent was accidentally introduced to a new environment due to "parasite passengers" in shipping containers. While this problem exists independently of genetically engineered moths, since this already happened before[0], creating a void in an ecosystem might make this process easier.

[0] the first thing that pops in my head would be chinese mitten crabs in Germany https://cutt.ly/1rTUHN3