Not really that much of a surprise. I've noticed superior aliasing in a few Pro games, though most of that was likely due to supersampling. This is probably just better AA.
It looks very good on the Pro, though I'd bet it still looks good on the regular ps4 as well, just jaggier.
Just been playing it on the standard PS4 and it really does look nice. The battles are really fast paced and unless you really want to nit pick there is some stair casing especially on finer objects like wires. You also have to remember this is a demo not the finished game.
What is interesting with the Nier demo is that you can select difficulty settings from easy through to very hard. Even on normal the game does not disappoint although I think I will turn it up a notch when I do a replay.
Note: You can adjust the difficulty on the fly and I have noticed a few games do this (ie. The Witcher 3, Skyrim ..). Personally, I never reduce the difficulty on the fly since that to me is a cheat.
I have just downloaded the Gravity Rush 2 demo and will play that as soon as I finish the Nier Automata demo. I have played Gravity Rush Remastered and I do think that is a really good game so I am fairly sure I won't be disappointed with the sequel.