Yes. It first copies them to the "Storage location for originals" as specified in the Preferences>Local Storage tab (you can change that location if you prefer), and from there Lightroom uploads them to the cloud. Once the initial import is finished, the original source for those imports is of no interest to Lightroom, the user can do whatever they like with them.
Once uploaded, Lightroom regards the cloud copies as the "masters", meaning that if you inadvertently do something to the locally stored copies there should be no consequences, Lightroom will simply download a copy from the cloud whenever it next needs a local copy (which it uses for performance reasons when editing). That's all pretty seamless, but if you do wish to changes the storage location for those originals, do it from within the Lightroom Preferences dialog and Lightroom will take care of moving them from the current to the new location. Moving them yourself outside Lightroom would simply result in a new folder being re-created in the specified location and new copies of the cloud masters would be downloaded again into the specified location.