I'd argue that most of the guys getting long suspensions these days aren't 4th line plugs.
Wilson, Wideman, Voynov, Torres, Cooke...
4th line plugs probably isnt the right term, I just mean they arent all that difficult to replace. A long suspension to me is 10+ games, the 20+ doesn't happen very often and some of the ones you listed are more than 4+ years ago, so does that really qualify as "these days"?
Voynov (2014) - season (not hockey related)
Torres (2015) - 41 games
Cooke (2011) - 17 games
Wideman (2016) - 20 games (not player related)
Two of those listed arent the result of incidents between players. The wideman (similar to Vermette) incident wasnt handled by the DPOS and the penalty is pretty much set in stone. The voynov thing was indefinite and he ended up being deported for breaking the law. No reason to compare either of those suspensions to the normal run of the mill suspensions IMO.
In the last two seasons (10 or more game suspensions)
Luke Witowski - 10 games (leaving the bench)
Radko Gudas -10 games (slashing)
Alex Burrows -10 games (Aggressor/fight)
*Vermette - 10 (slashing an official)
Then you have wideman & torres from the previous year. Excluded Vermette because his suspension isnt related to his on ice play vs a player, though he is easily the best player in the last few years to have a big suspension. Burrows was a far cry from his Vancouver self when he got suspended and was largely a role player. Witowski is junk and Gudas is a legitimate psycho who is semi-reasonable defensively. None of those guys are difficult to replace with other depth players. Most of the guys you listed arent either, with the exception of maybe Voynov. But again, he was suspended and deported, so that is what I would consider to be extraneous circumstances....
In summary, I dont understand the thought process that some posters have when they get upset that their guy being suspended for 10 games doesnt get roster consideration. First of all, those suspensions are rare. Secondly, these players being suspended really arent good to being with. I'm also quite sure that LA would have gotten roster consideration for Voynov so that doesn't even relate to this issue. The loss of a guy like Witowski/Burrows/Gudas (hes suspended all the time anyways) is hardly noticed when cutting a roster from 23 guys to 22 guys.