I'm going to have trouble ever liking the guy unless he undergoes a significant personality change, but I absolutely recognize how well he was developing over the 2nd half of last year, and I can see why they would be loath to trade him. Certainly it makes no sense just to clear a logjam. He's far too valuable.
(Likewise, I like Pionk, but he obviously struggled over the second half of the season. Frankly, I'm amazed they were able to acquire Trouba giving up only him; I thought for sure Skjei or ADA would be included – perhaps both.)
That said, with Keane and Lundkvist coming in the pipeline, and Fox now in the fold, there isn't room for everyone. And while we obviously have yet to see Fox play a single pro game,I have difficulty seeing ADA beating him out long-term. It may not happen this year, but I can certainly see ADA getting moved for value at another position at some point down the line. Especially since he'll start to be increasingly expensive soon. Only makes sense from an asset allocation POV.