Fear he could wait awhile to come over to NA, 2 years+. (Believe he's said he's not in any hurry)
And also position, Zadina fell as a concencus #3 winger last year. You've seen centers go higher than projected basically every year. There's 3 good centers (Turcotte, Dach, Cozens) & two of them with size. Then also a big gap between Byram & the #2D if Chicago wants a defenseman.