According to MLBPipeline, Abreu was the Astros #7 prospect with a FV of 50. His description sounds a lot like Touki, who is also a FV 50 guy.
The Astros now have Mac for 2/23 with a $15M option that is fairly likely to vest, so it's really 3/38. The advantage for the Astros in this whole scenario is they get to DH him while the Braves could not (but we won't get into the DH being an advantage for AL teams).
Would we be happy if the Braves traded Touki for Mac at 3/38? I think it would have been a clear win for the Yanks, and I would rather see the Braves just sign Castro for something like 3/25.