The Blackhawks are in no position to be turning down upper-echelon NHL talent. Timelines go out the window when it comes to fantastic players under 30.
They're going to draft in the top 3-5 again this year (conservatively). You just took Levshunov second. How much longer do we need to be cellar dwellers?
If Rantanen and/or Marner want to come, you sign the first guy of two that's willing to put his pen to paper. Rantanen is 29. There will be plenty in the tank when this team is ready to compete, and he's a proven guy in the playoffs. It also lifts the spirits of the young core (mainly Bedard and Vlasic) that the front office is trying to aggressively get out of the cellar.
The Blackhawks are an incredibly profitable team, and the Cap is going up. By three years from now, I think you can pretty comfortably pay three or four guys $10M+ AAV. You easily could at the end of one of these 7-year deals (unless you deal for their rights and go 8).
I'm not saying this will happen (almost certainly won't), but you could extend Bedard and bring in Rantanen, Marner, and Kaprizov if you really, really wanted to and they all three (for some reason) wanted to play in Chicago.