Well, here's the thing...Ubi was always close-knitted with MS and MS hardware than they ever were with Sony...Maybe they prefer MS hardware, but even the first AC was better on 360, though first announced by Sony and where many thought it would be exclusive at the time...Every other AC was better there too and it's understandable, but for something as basic as an AA Solution, Ubisoft kept a vaseline infested Quincunx AA on PS3 for several games, which made all PS3 versions blurrier, they only opted to change it till AC Revelations...
That was just a bit of history though. Beginning this gen, Ubisoft's model for development was based on XB1 hardware, maybe they thought it would be just as successful as the 360 seeing all the success their AC franchise received on that platform, but Black Flag was 900p, so was Unity and Syndicate...and of course we had titles like WatchDogs which had to be scaled slightly below 900p on XB1 because of the GPU...All these games were 900p on PS4 as well...Now, I'm not calling MS on this per se, I'm calling Ubisoft, because they clearly have a stronger relationship with MS or maybe certain clauses are stronger or should be adhered too a bit more under MS's marketing deals??
Why am I saying that?...Have you ever wondered why BlackFlag got a patch to 1080p on Base PS4 and Syndicate got a patch to 1620P on PRO and Unity never did? I think it's clear tbh. Blackflag amongst other AC titles could have launched at 1080p with much better AA, but yet they launched at 900p....even now, Syndicate is not 1080p on base PS4 when Ubi said they would patch it in, heh!, even the pro patch was a joke when it launched...So you see, Ubisoft are not as inclined to keep to any standards and clauses when they cut marketing deals with Sony...I guess it's pretty much common knowledge that MS's deals/contracts are a bit more strict and demanding in general.
So, it's not strange that Ismail is saying that ACO will look better on XBONEX, yet, I don't think any such statement was made for Syndicate on PS4..... It's simply because Ubi is a bit more well knit with MS...... Now, before anybody gets the wrong idea, I have complemented Ubi a lot recently...and though I think the AC guys have a better connection with MS....I'm really impressed with how the other studios have improved from the launch days and have now given performance and resolutions that matches the different platforms more suitably.....Primal, Division, WatchDogs 2, Ghost Recon etc...are all great efforts and should be commended...