It is kind of silly to think we are "altering" species. We would be creating new species or breeds using existing ones as a template. Unless there is some agenda I am unaware of to go out and kill all existing members of a species after we create our own version of it?
If nothing else, isolate the artificial species into controlled habitats. I know a primary use-case often discussed is regarding mosquitoes where that wouldnt be the case.. but imagine editing the genetics of zoo animals so that they are much more easily acclimated to zoo life. Less negative effects of poor temperature control, a broader dietary selection, reduced reaction times for dangerous animals. And there is no risk of environmental impact since they are in isolated enirovments