About the consoles versions stuck at 900p - well, that's not good for PS4 gamers. One of the big-sells of the PS4 was it could do 1080p; while the XB1 was a coin toss on if it's support 1080p or not.
Why announce it? So Sony gamers know ahead of time, before buying the game - don't expect 1080p support here.
I wouldn't be surprised if Microsoft tossed Ubi $, so they would have both versions running at 900p.
And, I wouldn't be surprised if later, PS4 gets a re-released AC:U Complete Redux HD 1080p Edition with base-game plus all DLC's.
Especially since releasing a game and then re-releasing it in full in HD-quality with all its DLC's seems to be a thing now - i.e. see Sleeping Dogs: Definitive Ed, Deus Ex: HR - Director's Ed, Metro 2033 Redux, Metro LL Redux, etc.
Given their "parity" stance here - I just hope the ACU PC version doesn't get locked at 900p @ 30fps.
We saw how Watch Dogs PC turned out, as it got basically down-graded to the console versions - again, that whole "parity" thing.
While I could tolerate 30fps as long as it don't dip too far when things get intense - the 900p is a not good for a brand-new AAA title on the PC.
I don't sit on a couch, a distance away. I sit right up to my 23'' inch monitor, very close. We need a higher-res here on PC, w/ that big of a monitor + sitting that damn close.