Why not just trade the rights too Kruger instead of signing him then trading?
What's the difference?
Not letting the Senators negotiate the terms?
Also, if I was Kruger and thought I was giving the Hawks a hometown discount so I could keep playing there (and avoid the hassle of moving to another city), I'd feel betrayed if I got traded away right after. If you had the trade already planned, NHLPA could claim it's "negotiating in bad faith".
Obviously it's not such a relevant thing when making fantasy rosters. Basically, if this trade was to happen, it'd be for Kruger's rights for that 1st rounder. And the end result would be identical.