If we were able to navigate the cap without gutting our team (i.e. eventually having to shuttle one of 13/79/45/74), sure, I'd welcome PLD. As it stands, we have too much cap tied up in too few players, and all of them have seriously restricting trade/movement clauses. Everyone is assuming that we'll be able to move one of 8/20 in two years, but we need to be able to build a cap-compliant team right now.
We have $12M in cap space with 15 players signed (9F/5D/1G). To move Nemeth, it's going to cost a pick we can't afford to move (probably a 3rd). Assuming Chytil is going the other way, that's another $2.3M.
Now, you have $16.7M with 13 players signed (8F/4D/1G). PLD needs a new deal. I don't think there's any way he's signing for under $8M on a long-term deal. Kakko will get somewhere in the $2.5-3M range on a bridge deal, but let's just say $2.7M That leaves you with $6M in cap space to fill out this roster:
Kreider-Zibanejad-Lafreniere
Panarin-Dubois-Kakko
3LW-3C-Blais
Motte-Goodrow-Hunt
Reaves
Lindgren-Fox
Miller-Trouba
3LD-3RD
7D
Shesterkin
2G
Schneider locks in the 3RD spot for $925k. Even assuming one of Kravtsov/Othmann grabs the 3LW spot for $900k and Jones/Robertson gets the 3LD spot for another $900k, that still leaves you with only $3.3M to fill 3C, 7D, and 2G. A scrap-heap 3C is going to cost at least $2M. A 7th D that you don't want to fire into the sun is in the $1.25-1.5M range, at least. A solid backup goalie is another $1.5M. You're already over the cap by a million or two, and I've used pretty rosy figures for the most part.
So yeah, maaaaaaaybe you can squeeze a roster with PLD in under the cap this season. But what happens next season when Miller and Lafreniere (and possibly Kravtsov and Jones) need new deals? The cap isn't going up by more than $1M, and all of your depth pieces already make a pittance. Sure, you free up $3.4M with the Girardi/Shattenkirk/DeAngelo buyouts coming off the books, but it's still not enough. All of our high salaries are locked in with movement clauses.