My opinion isn't only driven by advanced stats. I just think this is a classic case of a player outperforming his career numbers by a good margin in a bigger role than he's really suited for.
First of all, notice his shooting % this season is at 20.7%. That's 3 times his rate last year and double his career average. Considering that he has one of the worst muffin shots in the league I'd be shocked if he keeps that rate of scoring up.
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Secondly, notice that his TOI is up by 2-3 minutes compared to his time in Dallas. As shown in the charts below Janmark is also playing with 2nd line level linemates in Chicago compared to being a bottom 6 forward in Dallas last season.
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Possession metrics are also highly valued by GM's, and the fact that Janmark basically gets caved in everytime he's on the ice (which is what a sub-40% CF% indicates) isn't very appealing.
When assessing value you have to consider it from the perspective of a buying team. They aren't buying him to be a top 6 forward with the expectation that he's going to continue to shoot 20%. Rather, they'd be interested in him as a 4th line PK specialist. Is that worth a 2nd round pick? Probably not. Teams could easily just grab Glendenning or some other 4th liner for a lesser price to fill that sort of role.
That said, it's fair enough if Chicago dig their heels in and prefer to keep the player instead of selling him for less than a 2nd. That's their prerogative if they feel that they're not getting what they want. Though I would argue that they should move him for whatever they can get at the deadline so stock up on some draft picks during their rebuild/retool.