We won't need the cap space in the next four years anyway - Eklund is likely the only player who might be due for a nice raise during that time, given I expect Smith and our pick this year to need another year in college (maybe even if it's Celebrini), but this organization does seem unwilling to actually bench or waive Vlasic (which they should do - just waive him and tell him to go home, he won't and shouldn't be getting another game), hence the buyout (the "respectable" move).
It doesn't really matter either way - there are marginal benefits in each direction (cap space, contract space, playing time, "respect," etc). The answer should be to simply get rid of Vlasic so that we never have to see his decayed husk of a corpse of a career on the ice ever again.