Good points, but not convincing.
First of all, a weapon that can 'vanish' a ship that size is either pumping out enough energy that shielding and armor becomes a moot point as it will strip and desintegrate those in seconds, or shorter. And even though our oldest ships are getting a bit on in years, only the most state of the art (as in our very latest ships) have any upgrade in capacity that would make any real difference against such a weapon.
So either we have a weapon that can pump out horrendous amounts of energy, or is working on another kind of principle than energy transferal. (Creating dimensional rifts? Creating a localised temporary singularity? The possibilitys are easily in the thousands.) And against such a weapon there would be no defence, as the opponent would simply not know what to defend against.
Second, propaganda is a valuable tool in all kinds of warfare that is true, but propaganda only works when you can say "Hey! Look at us! Look what we can do!" and then demonstrate in some appropriate impressive manner what your new toy can do. Setting it of and then let the scuttlebut run lose will cause nervous feelings in all factions. This case being OT, Clans, Neutrals and ICC, not to mention pretty much everyone else. And that´s just not good for business.
I was trounced over the head with that statement too, and i´ll agree that it does have merit. How ever, for a general to go through an entire career without having to engage in battle shows that that general is either working under an era of peace, or is one of those "General in charge of procuring rivets" desk jockeys. And i can tell you that it takes one hell of a general to go through an active career undefeated. It happens so rarely that i for one can´t think of an example through out history."A good general never looses a battle, a great general never has to fight a battle."
Propaganda is top of strategical, yes. How ever, the "publicity" you are refering to in Ops and Tactics is called "Keep it silent, keep it secret" and "Disinformation". The old saying "Lose lips sinks ships, breaks hips and spines and skulls" is still true. When going active you don´t want the enemy knowing anything at all what you are realy up to. They can chase all the spooks they want, but you want the surprise 100% on your side if at all possible.That means that publicity is a very important tool in warfare. It's tied for first place (alongside logistics) when talking operational and tactical issues but it stands alone at the top strategically.