That's most unlikely for two reasons. First, Moiraine had no certainty she'd come back, as she wrote Mat. Unless for some reason she saw signs (ie: in Rhuidean) that she musn't tell him anything unless she returned, it seems too foolish for Moiraine not to arrange to give Rand her information, in case she did not return.

More importantly, Moiraine implied to Rand that she couldn't think of a way to ask a question about the DR or the LB without touching on the Shadow, which is punished by the Finns (which is why Moiraine never planned for Rand to go ask questions. She deemed it too dangerous for the DR). That makes it kind of unlikely that Moiraine got out of the Finns anything related to defeating the DO or sealing his prison. What she might have risked asking, and IMO probably did ask, is how she could help the DR. She would have gotten a riddle out of this, and possibly she had not puzzled out anything useful out of it (and based on her growing frustration around that time it could also have been an answer she didn't like much beside not understanding much of it) before she disappeared, but now has.

As we saw with Rand - who got lucky - the key to get answers and not punishment for questions touching on Shai'tan is to make sure it's a question about yourself. The Finns can see in your own future. Rand could ask about defeating the DO and surviving because it's directly related to him. Had Moiraine asked how Rand could defeat the DO, she would likely have got the "punishment".