The team is in the playoffs during what was a rebuilding year. Yes, I agree that much of the talent was already there, but you can't argue with the players that Bloom picked up that turned out to be key players. He did this while staying under the luxury tax limit and, most importantly, while strengthening our farm. Depending on whose ranking system you use, the Sox farm improved by about 11 spots this year. IMO, that's pretty incredible.
That said, I would still give larger credit to Cora for this year's turnaround.