That uncertainty is absolutely baked in. I know it is in Pecota because they output percentile projections. I have backed those out before and looked at them, and they tend to make sense. The ones on Fangraphs have to have that built in, and whatever internal go/no-go the Tigers have will bake in whatever they think it should (and could include biomechanic/swing/mechanics data they have on some of the players). If there was no uncertainty in the projections, every team would be 100% or 0%.
They aren't perfect, but they get you in the ballpark, and no matter what marginal improvements you make on the projections, the Tigers are still in a "sell" spot, but that could change by the end of next week with a 10 game winning streak.