Check out their roster situation. They only have 15 players signed for next year, $5.3M in cap space, and only 3 players on defense signed (Hedman, McDonagh, Coburn). Sergachev, Cernak, Stephens, Cirelli, Verhaeghe are all RFA. Maroon, Rutta, Schenn, Shattenkirk, and Bogosian are all UFA. Those are some pretty big pieces they're going to lose. I understand none of those guys are the main pieces (aside from Sergachev) but it'll be impossible to keep them all. They also have 8 players with either a full NTC or NMC, then Killorn with a modified one. I'm not quite sure what team they're icing next year. Good thing they won it all this year.
I assume Killorn will have to be moved to help create space, he's the only one movable with a decent salary.