I think you're right, but this is confusing and not explained well at all in the article. I had assumed the article was mixing up "plug" and "port," because it doesn't make much sense for the jack/port to be large enough to accept an existing plug - if you're trying to make it thinner by cutting the plug in half, you're not going to keep using a 3.5mm cylinder for the jack. I can't find the patent application with the illustrations, but it sounds like they're covering a bunch of applications including a jack that has large and small ports, small-port only jacks, and magnets in the large port hole to keep a half-plug held captive?