Winning the lottery does not give you the first overall pick, it moves you up 4 slots. You can only have a chance at the first overall pick if you are in the bottom 5. NJ won the lottery last year and picked 5th I believe.
I'm pretty sure someone explained how it works to you before.
My blind guess would be Carlson getting moved. Matches the (manufactured) hype and still has value around the league. Team just signed an offensive D prospect as well, and obviously likes both Oleksy and Kundratek.
First, let me say that I absolutely do not think either Kuz or Forsberg is on the trade block.
But let's speculate at what kind of return would be needed for such a huge prospect. Philly had to give up Mike Richards as the principle piece to acquire Brayden Schenn, who was a roughly equivalent prospect. I can't really think of a player of that caliber who could be available.