Mosquitos are food for hundreds of animals. Doesn’t take a genius to see where this ends up.
They did 20 million sterile skeeters (9x this story) around FR HQ a few years back...no noticeable change in the ecosystem. Human activity (feeding Canadian geese in ponding basins so they never return to Canada/feral cats eating birds, etc. are a bigger factor locally). Mosquitos need thinning like deer due to lack of natural predators like bats in city urban areas would be my take on it.
Fresno/FR HQ release:
https://newatlas.com/verily-mosquito-release-wolbachia/50521/