While Kirk does have the most value, I don't think the Jays will move him. It's going to be come down to Jansen or Moreno if they have to move anyone, IMO. Initially my thought was they'd trade Jansen in the winter, but I'm not sure anymore. Moreno likely fetches the better return, and more teams would be in on Moreno than Jansen. Pretty much only contending teams would trade for Jansen and they likely wouldn't subtract MLB talent for him, so hard to find a reasonable deal there. Moreno would interest every team looking for a catcher, and rebuilding teams are the ones who would trade established MLB talent for prospects, so that's likely the more reasonable move given the team's timeline.
Of course, they could move Moreno to a different position and keep all 3. It's a great problem to have.