they won't do this unless they can move JJ and even then I don't think they do.
They have depth options next year at LD. Almari, POJ, and Riikola.
I don't think they are going to chase a LD.

Fleury is a promising player who is NHL ready.
I don't think POJ will be ready next year.

If you watch the WBS games you would probably see that Almari is also NHL ready. Easily for a 3LD. The argument could be made the Riikola is as well.
What won't happen is the team won't hold 3D in scratches. On top of it he'll need a new contract and this team is going to be spending a lot on defense with MP and Marino needing contracts soon.
Which is why I don't see them doing this. They will fill the LD from with in because they have the prospects to do so.
They will then chase a RD which they don't have as Addison is not ready to play at the NHL level.

You have to pick and choose your battles. There is only so much cap.

With the inevidible injuries to our D,
I'd love to have all those guys as spares.
Fleury is arguably better than what we have right now. Almari could be a solid call up, he's still very young.
I like POJ but I haven't seen anything impressive from him right now. He's pretty lanky and needs to bulk up.

We normally lose one of Schultz, Letang every season.

you guys wont be able to resign him, he wont resign with pittsburgh