I don't see any urgent need to choose between a prospect in Double-A and a prospect in Single-A, which is what Margot and Benintendi were at the time. I'm happy with the Beni/Bradley/Betts outfield we have set for the near future, but still having Margot around (or having been able to trade him for other needs, as Moon mentioned) would be attractive as well.
Ultimately, there are reasons to like or dislike the Kimbrel trade, but the argument that Margot was "blocked," so who cares what we got for him, never held water for me...and I'm putting this out there not out of some desire to rehash the Kimbrel deal for the umpteenth time, but because I anticipate similar discussions being had about Devers in the near future (assuming we sort out the 3B/1B/DH situation at the major league level this winter). A player who's a year or more away from being major league ready is not "blocked" in any meaningful sense, simply because so much can change in that time.