I doubt they have ever officially said "it will never run backwards again". Perhaps something to the effect that there are no plans to run it backwards again, but it wouldn't be good PR to paint yourself into such a corner with the words "never" on such a subject.
It may not have been designed to run backwards and PTC instructions may instruct them to only run it forward (though I've always felt this was a dubious claim, instructions were likely how to mount it with no mention or thought to ever reversing the seats on the train.
The ride had a rather lengthy history of running one side backwards with few to no incidents that I'm aware of. I doubt it would be that hard to have an engineer or design professional form an approval letter for running it backwards again if that is all it takes.
Its always been my belief that PR's claim that they turned the far side around was primarily because that is the way it was intended and originally ran to bull. I believe the main reason they turned it around was so that both ride experiences were essentially the same and on slow days or at park opening, they could keep one side running, and the other side down and not take anything away from their guests. I don't recall if ridership (at least when I was there) was significantly less on the backwards side or not, but that could potentially play a role as well if the general public just didn't like the backwards experience near as much. Personally, I always loved the backwards experience and it always gave me a reason to ride it twice on each visit.