I don't think they "tried" to move Miller, Boeser, or Garland. There was no preasure to move any of them as none was a pending UFA. They were certainly willing to listen to offers but unless an offer blew them away there was no real reason to move any of those three last deadline, at the draft, or even in the offseason. Listening to offers is not the same as trying to move a player.
They re-signed Miller to avoid losing him for nothing? They had till next spring to move him if they didn't want to re-sign him. As a pending UFA they could have simply taken the best offer and moved him. Preasure that was lacking last spring. I think 8m for 7 seven years was a reasonable deal and that's why they re-signed him.