Does a written oath that has not been uttered take effect, noting the existence of a previous membership that was suspended?

There is no blame upon you for registering yourself with a new name on the website, so long as your previous membership has been terminated, because it is as if it never existed, and you will not be considered in violation of the website's terms by doing so. As for the oath which you did not utter with your tongue, it is not binding, and you are not considered to have sworn it, for an oath is only valid through verbal utterance.