From the rubric article:
What happened to Papadopoulos [George P.] was a classic way for Kremlin-connected individuals to infiltrate the Trump campaign. The game plan is to latch onto a low-level staffer, meet with him or her, and use him or her to set up higher-level contacts in the campaign.
So it’s possible that Papadopoulos also has a lot to tell Mueller’s team about how Kremlin-tied people tried to finagle their way into the heart of Trumpworld.
It’s an amazing story that appears to come out of a bad spy thriller, but it’s real. And if Mueller could keep all of this secret for so long, who knows what other publicly unknown information he has in his back pocket.
First:
"Kremlin-tied people tried to finagle their way into the heart of Trumpworld"
That Kremlin-connected folks would try doing so is something people should expect would happen. What's astounding is that, based on the George P. information we've received so far, that key figures in "Trumpland" exhibited no measure of circumspection about the possibility that that was happening; moreover, were acquiescent to letting it happen. Naive, nefarious and ignoble has always been an ill fated admixture of character traits. It seems we again see evidence of exactly that.
Second:
"Who knows what other publicly unknown information he has in his back pocket."
The answer is obvious, but that that is the answer makes the word "yet" quite fitting as the terminal word for pretty much anything the WH/Trump may have to say about the "Russia" investigation and his or his key advisors' interactions with Kremlin-driven individuals.
Third and not related to the rubric article:
George P. was trading emails with the second most senior person on the campaign team. That does not happen between a veritable "nobody" and the CEO of any organization. The claim that the WH is claiming that George P. was a minor player of sorts is preposterous.