Macko is sidelined for at least a couple of months as he recovers from a meniscus tear before official ST games began.
Bloss could certainly do well out of the BP, but I think his role for now is remaining stretched out in case some of the fringe options like Bowden Francis and Yariel Rodriguez struggle out of the gate. I think it's almost a near certainty that, barring an injury to himself, Bloss starts at least a handful of games this season. And if his home is in the rotation permanently, which the Jays certainly want as their key component of the Kikuchi deal, then he'll need to continue building up his innings.
There's no doubt for me that Bloss is the next man up in the depth chart after Francis and Rodriguez. With Scherzer and a lot of the rotation members being kind of old, I wouldn't be surprised to see stretches of a 6-man rotation under consideration.