Supposedly they bead blast the hood, using steel beads, is supposed to be coated with a primer that prevents steel rust from the trace steel left behind. They failed at that quite a bit I have been told. The body shop who fixed it was supposed to use a similar priming agent. It didn’t work. Now it’s only a few months since the last painting. Let’s see what happens after 2-3 years.
Whoever told you that lied. Steel bead blasting would rapidly erode an aluminum body panel and would create bimetallic corrosion under the paint unless they surgically cleaned the aluminum.