Board Thread:S,R,&G/@comment-3014077-20170613144725/@comment-27384850-20170613155508

I'd hardly call their early history being changed a "huge retcon", the fact that they didn't party together until later on is mentioned in passing and doesn't really play any role in the story. Not to mention the fact that their history together is changed in the main light novel series alone, from the two having only ever spoken in boss meetings and Kirito making note that they'd never so much as been to a restaurant together (v1) to them partying together and going to a restaurant to work on solving the murder mystery (v8). This is even changed once more in the main series, where Asuna reminisces about her time meeting Kirito in the dungeon and them partying together on the early floors of Aincrad (v16). It's a detail that not only plays an almost nonexistent role in the story but one that is changed multiple times within the main story alone.

As for Kirito visiting Asuna's house, there's more than one reason for that. While this is not a major thing either, as it is merely another thing mentioned in passing, but it has to do with the original intent for Ordinal Scale. The story of Ordinal Scale was originally planned to be set after Alicization, as evidenced by Material Edition 22 and (I believe) directly stated by Kawahara on Twitter, and thus it stands to reason that something like this event was intended to take place later on in the story. Instead, Itou seems to have left this event in the movie despite having moved its location on the timeline, causing a break in continuity. I, personally, take more issue with this because it raises questions about movie-version OS's status as canon, whether or not Kawahara will release his intended version of OS (novel format, set after Alicization), and what this means in regards to the anime v. light novel timeline.