AFAIK there hasn’t been a response on this, I have assumed it just the logo in the wrong place.
However, there is another interpretation, and it’s what I personally employ. As Chain Rifles are “cheap and easy to build” you might consider them to only gain the Concilium Restriction whenever the Tarif triggers.
Perhaps this represents some weird build process being involved or just that the construction of the weapon triggered some alert in a database somewhere, the description of these guns always reminds me of a Ripper from 40k in that most are scratch/hand-built and that the ones with a triggered Tarif represent the few well-made industrially produced models that have been declared as a restricted item.
Remember the icon is applied to weapons capable of destroying cubes and Spread weapons are really good at turning things into little chunks.
As for Shotguns… its because of the Ammo types they can get that they have this symbol, only AP Slugs don’t have the Concilium Logo so why not make Shotguns restricted as well, they are a pretty indiscriminate weapon by the time of the Human Sphere.