The cordova.define are now inserted by cordova around the js defining a plugin.
(In the SalesforceMobileSDK-CordovaPlugin repo, I have a script that takes cordova.force.js and generates a js per plugin without the cordova.define(...) around it).
the value that goes into the cordova.define() call is based on the id of the plugin and the name of the js -module (appended together with a ".").

<plugin xmlns="http://apache.org/cordova/ns/plugins/1.0"
        id="com.salesforce"
...
  <js-module src="... name="plugin.oauth"></js-module>

So it was not possible to keep the old plugin name.