How does any of this validate Velikovsky?
As it becomes more and more difficult to justify the perspective that these comets were created at the time of the formation of the universe, an obvious alternative is that they formed by a different process. Also, as comments quoted in the article indicate, it would be hard to imagine the coma oxygen having survived for such a long period of time, which implies that the comets may have formed much more recently.
Carl Sagan noted that Velikovsky's scenario for the origin of Venus should also have created many smaller bodies. From many different perspectives (including this new one), comets have the right attributes to constitute some of those smaller bodies.