I didn't understand the forever part, not that I understand ANY of the cap rules and implications of LTIR.
The forever part more applies to teams that plan on utilizing LTIR for the entire season, of which there are a handful.
This doesn't really apply to the Devils though, since it appears that Bernier will likely come back at some point this year. If you know that a player will definitely be out all season, then you want to get as close to the cap as possible to replace as much of that salary as you can.
In the Devils situation, their current cap hit is $84,833,292.
This consists of the 14-7-2 players named to the final roster (which includes Johnsson), the Schneider & Kuokkanen buyouts, Kovy's recapture penalty, Nico & Thompson's cap hits on IR and Bernier's cap hit on LTIR.
That $84,833,292 is $2,333,292 over the cap. They could've gone up to $86,625,000 if they would've fully utilized Bernier's LTIR, but they left $1,791,708 in unused LTIR funds from Bernier's $4,125,000.
I'm just not sure how things work out if other players go on LTIR this season while Bernier is there and if that could hurt us in not utilizing that space. But, given that Bernier is expected to return there's not much else Fitz could've done. Having Nemec on the final roster was a no-brainer as all it is is a paper transaction between him and Bahl. There were no options for such moves at forward.