Yes, I know that the WoG isn't final on this. I would like to point out that a fairly large amount of noise is/was made over Kirito visiting the Yukki household and meeting Asuna's mother. Both of those events are clearly stated as never having happened in SAO9, which happens after OS. Also, there is the discrepancy of the release date of the Augma.
In contrast, I would like to point out that there are things in Progressive that are also clearly pointed out as not having happened in earlier LN. One specific example is the first time Kirito and Asuna formed a party together. The original LN say it wasn't until the Murder Case in the Area, while Progressive has them partied up (so far) thru most of the first five floors.
Both stories are considered to be canon. Anyone want to address why there's such a fuss over what I consider minor retcons, that Kirito went to Asuna's house and met her mother, but the a huge retcon of Kirito and Asuna's early history is quietly accepted?