I'm confused why this keeps saying indoor, when it just seems to be talking about a more modern "raceway" system that has been used since at least the 80's, that I know of. Everything it described sounds exactly like the farm my dad used to run, except inside. The "indoors" part just sounds like a more expensive way to do raceways and probably isn't needed in most cases.

Can anyone explain the difference? Or is "indoor" just a buzzword here?

I'm all for more fish farming. Raceways are extremely efficient. During harvest season we were harvesting around 30,000lbs of hyrbid striped bass every 2 weeks off half an acre, with just my dad running the farm and me helping with the grunt work. We also had a few of the unused raceways dedicated to Tilapia as a side income, which were basically self sustaining and just needed to be fed. They bred faster than we harvested them.