They've pretty much played Hallowed a million times over the past (more than) 25 years. I'd be surprised if Dave wanted to play the solo exactly like the studio version even after a few years. Heck, he probably does keep key parts in and improvise around them, but by now all his "key parts" were not even in the original song. Things tend to change like that. (for a more extreme example: Bob Dylan.)
"So yeah, monkey prostitution has happened."