That is not really a problem of Cordova but of two of its plugins clashing with each other. Search for the error message here in the forum and you should find several solutions.
Good question, but also not related to Cordova. Maybe ask this here? Ionic 3.7.0 and App-Scripts 3.0.0 are out! You could also look through the app-scripts code on Github, maybe they just forget to change the output?