Webpack/Parcel would package all different versions of one dependency in the bundle, the output format use array or object to store the dependency name-module map, so it just use different key for different versions. Ember-cli output AMD modules, I think it would be a little bit tricky to achieve the same effect, it will increase the bundle size, but I think this is the accurate and safe way.
@rwjblue Will ember-cli support packaging all versions of one add-on into the bundle in the future?