They were both offered contracts. One accepted, one did not. Bo wanted a chance to earn a larger one, he increased his offers, and still hasn't signed. He seems to have his sights set on a new team. That's more his choice than the teams. If Bo isn't accepting 7-8m offers, then there's not much that can be done, takes 2 to tango.
Position has nothing to do with it, original offers were made after 2 very shaky years from EP, and a broken footed Bo. Their ability to be swapped was seen as a big strategy and strength going forward.
JT is one player, he's not keeping them from signing Bo any more than anyone else. If it's about money, then really they've chosen not to bite the bullet on guys like Boeser and/or Garland over keeping Bo.