This sort of bio-engineering can have possibly far-reaching and disastrous results. These insects are major components of various food chains .. Bats, e.g., depend on them .. and where bats comprise 25% of earth's mammalian body-weight, it's clear the ramifications could be tremendous..
It might be best were they to obtain a 'switchable' lethality approach . .. where there'd be less risk of total destruction of all mosquito populations, whether they be part of a disease cycle or not .. It's the 'nots' that would be key, here ... I should think.