Unless Sergachev slots in as our #1 LD, and I'm not sure he does, then I'm lukewarm on the idea.
Similarly I'm not all that thrilled in bringing in a clear cut 2C like Lindholm or Monahan.
I'm more interested in finding a future 1C even if that means having to get someone who is further away.
But we have plenty of middle-6 and middle-pair options already. We don't need more, they will just take time. Hajek, Rykov, Reunanon, Schneider, Robertson, Jones, Miller, Skinner, etc, etc, etc. We are gonna have all the quality "top 4" D we can handle and then some. So if Sergachev is merely a quality 2nd pair..... eh..... I'll just wait a bit longer and then have enough organically and for cheap.
It's a 1D that my system might be missing, just like it's a 1C that my system might be missing for the post-1C-Zibanejad era (there is no one around necessarily who projects as that top center for when Lafreniere and Kakko are 25 years old). 2C isn't nearly as much a concern; if I have Eichel, then Chytil is probably more than enough at 2C with these wingers. And so on.