Definitely.
But I would be tempted to offer him a loooong term contract next winter and ask him to start.
He might get offered something approaching 5/$80 to close. I believe this would be both a record AAV and and term for a reliever. Here is the top of the historical closer market:
Papelbon 4/$50
Soriano 2/$28
Robertson 4/$46
Rivera 3/$45 (back in 2008!)
Maybe some team offers him 6 years but haggles the AAV down (6/$84?).
I think some team should offer him a contract over $100M in total value, under the condition that he converts to a starter. If he fails you can always pull the plug and move him back to the bullpen. The guy will still be sort of young, he would probably still sit ~97 which would be the best in baseball for starting pitchers. He has surprisingly clean mechanics. He has three pitches.
Do it, Toronto!
I wonder if a team could sneak into the Chapman market late, offer him a more lucrative contract than any other team while asking him to start, and be able to get him for less money than Kenta Maeda will cost this winter.