Even if Arvidsson doesn't "bounce back", you're presumably still getting at least a pretty solid 15-20G, 40-50pt winger who hustles and works hard. His deal certainly doesn't look like the steal it once did, but even at ~$1M per 10pts, that's not really much off the going UFA "market rate". Especially considering it's pretty "goal-skewed" which is worth more than just collecting secondary assists, etc. At his age, it's doubtful Arvidsson really "rebounds" to full peak form and production, but there's clearly at least a little bit of headroom there for him to be more productive than he's been the last couple years, if the fit is right and he clicks in LA. Which could take it from an "okay" deal, to a "really good" one.
Kind of strange from Nashville's end, in that it seems like they need more scoring up front, not less. But they obviously feel like they need to shake things up and "retool", and there are only so many real "moveable pieces" to give you that shakeup. It's a decent enough return, and opens up a bit of cap space to play with. Those picks could even just end up being additional trade capital to go after something they really want, to give them a different roster composition. Flexibility is always nice...though what they actually do with it, is what will really determine how they make out on their end of the deal.