Amol did my haglunds surgery in the Spring of 2013. I had minute tears (slight fraying) in my Achilles and he detached it and reattached after cutting down the haglund to what he thought would be more manageable on the tendon. Much like you, Rojo, he told me it would feel better after 12 months, which was the amount of time it took my other Achilles to heal after having the same surgery done by a highly renowned surgeon in Baltimore two years before.
Unfortunately for me, the heel took 2.5 years to heal to a place where I could train with any consistency and another year after that for it be pain-free. It effectively ended my collegiate career, and I know it did the same for Dan Lincoln's professional career (same surgery with Saxena).
It will be interesting to see how Galen comes back from the surgery with Nike's resources behind him. Not surprising that he chose to go with Amol given his close relationship with Salazar, but it seems like a gamble to have him do this specific surgery.