I think Trump had inside intel before ADM Rogers ever came to Trump tower. In fact, that whole thing (Rogers briefing Trump) could have been a put-on to maintain the ruse to not tip off the traitors that Trump was on to them the whole time. It is basically chess. Make a move and sit back and watch your enemy make a response to judge their tactics.
I you look at Trump’s tweets, it looks he’s had a bit of insight since 2013.
In August or September of 2016, Trump went to California "to campaign". Most of us and most experts thought that he was wasting his time campaigning in California.
But what's worth noting is that Trump was campaigning with the House Intel chairman, Nunes. Nunes even flew on Trump's plane.
I think Trump may have flown to California specifically to meet with Nunes and to get the "inside intel" at that time.