I don't think so. I think it's more of a case of treating a veteran goalie who has been really good for you for years well. It wouldn't make sense to leave Koskinen rot on the bench when they are both playing at a similar level. Because Koskinen is a proven commodity, if playoffs started today I would start him over Shestyorkin without thinking about it twice. So yes, they obviously want to keep Koskinen happy but at the same time I don't think it has anything to do with Shestyorkin possibly leaving to NA in the future.
Overall, I think a lot of NHL fans often don't quite realize the fact that guys like Koskinen or Koshechkin are stars of the league. Sitting them on the bench to let some 20 year-old kid play is a pretty big deal. Cam Talbot was completely outplaying Lundqvist in 13/14 for example, I don't think anybody even thought about letting him start in 50 or 60 games because that's just not done. Those are kinda similar situations.