If that's what the manufacturer calls for, then it should have ATF put in it.
It's funny this subject popped up. I was at Advance yesterday picking up some donut gaskets I ordered. A lady came in behind me, holding a new quart of ATF, then went to the counter and said they sold her the wrong stuff. Said her boyfriend said it had to be PS fluid. The guy at the counter told her it called for ATF and I could tell she wasn't believing it. So then I piped in, lol. I told her it was true, some manufacturers call for ATF in the steering system. She said thanks and said she would let her boyfriend know it takes ATF. I don't remember what the vehicle was, some boring SUV thing that might have been 10 years old.