Just a throw away theory....but what if ComStar did stumble upon the remnants of the Wolverines and they did offer them sanctuary on the Hidden Five? But! And here's the theory: what if that is all that happened? The remains of Wolverine simply adapted back into civilian life on those forgotten worlds and faded into the past? They didn't become a super secret sect at the heart of ComStar. They didn't plot revenge on their former Clansmen. They were simply tired of war and faded into civilian life. As far as we know (or at least to the best of my recollection), the MD came from Jardine. So it can be safe to assume that they weren't settled there. They gave ComStar some information about the Clans, but not how to find them. (Even after all that happened, would they really want to see the Inner Sphere bringing war to the Clans?)
So basically, they met up with ComStar and made a deal to trade information in exchange for being given somewhere that they could settle and live in peace. (And how many survivors would they be of the group that supposedly met with ComStar? Several hundred thousand? A couple million? On the scale of the Inner Sphere, that's minuscule and if their world was kept strictly quarantined, it wouldn't be that hard at all to keep them a secret.)