Gosh...
No one is saying trade Sorokin (well unless 1 of those 2 things you mentioned above comes to fruition), so let's not put the spotlight there. Sorokin is a top 5 goalie in the world right now in his prime and if you can build around him...You 100% do that.
The real issue is this...Even with having a top-5 goalie in his prime the Islanders barely made the playoffs. And unless Lou magically improves this lineup in the next month it's going to be the same next season.
Whether it is Ovechkin, Crosby, McDavid, or anyone else...One elite talent can only take you so far. You usually need more, and the Isles roster outside of goalie is entirely average (and aging). And given how Lou has painted this team in a corner given the lack of cap space and assets to trade, I don't see how he's going to significantly add to this team to make them the kind of roster that can reach the final 4 (or better) again.*
*I know...I know...We shouldn't talk now. Let's ignore his past work and see how Lou does this offseason.