The
Old Testament certainly doesn't
disallow additional scripture - there were literally thousands of texts added to the
Jewish cannon over the two
millennia or so since the original corpus of the OT was compiled. Not only that, but at the time of its
compilation there were texts which were considered for
inclusion and eventually rejected for various reasons, and they remain part of the Jewish scriptural
tradition under the name "External Books".
By this reasoning, any book which is accepted by the religious authorities and/or luminaries of the time can enter the culture as a valid and binding religious scripture, even though the actual structure of the OT is accepted as cannon and I don't think anyone will consider re-editing it these days.