"And if they did close the canon, were they implying that they knew there would NOTbe more Divine Revelation to transmit to future generations from that time forward?"
A good explanation of such topics from a traditional Jewish perspective can be found at
http://www.simpletoremember.com/
generally, and a good audio explanation of Oral Torah specifically at
http://www.simpletoremember.com/media/a/orallaw6/