Most of our Intelligence Gathering efforts were not focused on Internal Karak (and Ulrikadin) Intelligence, but rather on external enemies, such as the Skaven and Greenskins. So, we did do part of our duty as a Grey Magister, but directed against the enemy without rather than the society within.
Come to think of it, did we even spend a single AP on internal intelligence? I recall that every single option to establish an internal intelligence network, such as the Ranaldian Underworld was decisively voted against because internal intelligence is not our job as the Loremaster. We haven't even created our Internal-facing Intelligence Network yet, and have been holding on off on it for the past seven turns. It's not surprising that the narrative consequence of this vote-pattern is that Mathilde failed to draw the dots regarding the Nordland migrants, anymore than I won't blink if Proscribed Cults are gaining a foothold in the Eight Peaks without Mathilde's awareness, since we didn't take the actions that could have averted this outcome ahead of time nor have we gotten eyes on Karak Nar until recently.
Again, I object to blaming Mathilde - there was no way she could have focused on things like Death Towers and robbing Queekish out of the Skaven and shanking Warbosses and murdering Alhkarad and his college and build an internal intelligence network on top of all that. And indeed, the thread turned down multiple chances to build such a network. Does it mean the thread acted in bad faith regarding the Grey College? Surely not!
You sold me on the rumor mill. Let's at least get an idea of what the word is on the streets before doing things like Paramilitary Navies or recruiting Intelligence Handlers. Let's start with the basics before going for sensitive information indeed.
Remember, we can't open the Karaz a Karak Herald or the Altdorf Times to give us a read on publically available news. The rumor mill is the closest thing we are going to get to the newspapers, and would give the thread much more context to work with.