Many "ecological niches" end up being key to the whole ecosystem. Mess them up and the whole ecosystem is messed up. The system is so complex that it's hard to know beforehand.
Aedes aegypti is an invasive species in that area. It is not a normal part of the ecology. Even now it is only about 4% of the mosquito population. Removing it would not impact other creatures that prey on mosquitos in general.