No option to tell Tanner about the Cube situation if you got there via Phreak

[Barry]

I've done zero quests for the Oligarchs and have never interacted with the Faceless at all.
The only person I interacted with related to the Cube was the train operator and knew about Terry and Lora's fates.
Confronted Cornell, eventually progressed through Phreak's storyline until I was in the research laboratory.
Got a quest to infiltrate the Institute in my notes, but no option to update Tanner on the situation of the Cube.

[ShoggothWhisperer]

If you haven’t done the rail crossing quest/completed “find what the faceless are looking for”, Tanner hasn’t asked you to find the cube yet, so the player character wouldn’t know he wants the cube. The infiltrate the institute quest is the characters personal motivation, similar to how you get the quest to continue exploring the Black Sea after being fired from the expedition.

[Barry]

I mean to be fair the character did make some mighty leaps of logic with all the dialogue options available but I see your point