I imagine that Frontier was surprised how fast Jaques station was found. Or did they gave the commander a hint?
Not exactly a hint. What they did was, they made the system show up in the galaxy map as "independent" which means that in map mode, it was colored yellow if you had that filter active.
But no explorer would ever have that filter turned on, because outside of the bubble, there aren't any fed/alliance/empire/independent systems. Explorers filter by stellar class. So no explorer would have found Jaques - most likely.
The guy who found it was actually still inside the bubble. He posted on Reddit that he was just zooming in on nebula looking for stars with odd names, and he was surprised to find a yellow (independent) system.
And I agree with you that Frontier was probably really surprised that someone found it.