The --link-to flag is no longer creating a symlink to the specified location. Verified that this works in 6.2.0 and breaks in latest 6.3.1 release.
I believe this is the commit that likely introduced the breaking change but I have not validated that claim:
Example command for reference:
cordova create testapp com.example.testapp testapp --link-to=/Users/ericb/examples/www