Sorry to tell you, but that is totally false. I had my SR500 soda blasted - no paint left and the surface was perfect for painting. It does not take away metal, that is the main advantage. Possibly easier to clean afterwards too... and maybe you can brush your teeth with the left over soda.
It will take off corrosion, rust, paint, etc, but not damage the metal. Key point - it will not damage exposed threads. Not a single one of the welded on threaded fittings needed chased or anything else. The work was so good it almost looked like the paint was chemically stripped, the metal was that clean and no coarse pitting like sand blasting or bead blasting. Car people love it because it will not cause issues when the sheet metal is really thin, like warping panels and such. I love it because it doesn't hose up threaded holes.
I learned about it when I spoke with the guy who did the work in Worthington Ohio, near me. He was at the Goodguys Streetrod Nationals at Columbus, with a frame on a rotisserie and I think a cab from a vintage truck sitting there bare metal.
One point though. If I was doing an older European bike - aka doing a Bultaco - I'd do bead blasting on the cylinder and head. It is pretty much a match to the original cast look. Sand blasting leaves a sharper unnatural look on the head. Then paint the cylinder black as usual for a Bul. As smooth as some of the Japanese stuff was it might be wise to do the soda blasting there too. No aluminum removed, but the surface comes out clean of any paint, grease etcetera.