Here is a more cut down detailed translation.
「DLCの物語に関しては、本編で描かれなかった部分を描くだけではなく、プレイヤーの遊び方によって結果が変わっていくようなものも予定している。 In regards to the story of the DLC, it will not just depict what wasn't depicted in the original story, but there are plans to implement something like where the players playstyle will change the outcome. あくまで本編の物語を変えるものではなく、DLCであればこういう方向でも楽しめる、というような幅を持たせたい。」 It must be said it's something that will not change the story of the original story, but we want to allow people to have this kind of freedom, where as a DLC you can enjoy it in this kind of way.
Going over the specific line. あくまで本編の物語を変えるものではなく - akumade honpen no monogatari wo kaeru mono de wa naku あくまで - akumade - This is kinda of a difficult word to translate, but it can be translated into as 'nothing more than'. Example ''akumade watashi no iken desu'' would mean ''it is nothing more than my own opinion''. 本編 - honpen - Means ''original story'', in this case it refers to the original game. の - no - Possessive particle, example combined with ''honpen no'' would be ''the original story(s)(stories)'' 物語 - monogatari - Means ''story'' を - wo - This particle indicates the topic before the action. 変える - kaeru - ''To change'' or ''to alter''. もの - mono - ''Thing'' or ''object''. ではなく - dewanaku - Simply ''is not'' or ''it is not''. Example ''puromuto wa ouzoku dewanaku, shimin desu'' - ''Prompto is not of royalty and is a commoner''.
The script can't be rewritten, so the events that lead up to these new endings have no bearing on what Kazushige Nojima and the other three already wrote. They wouldn't change the outcome of the final gameplay segment and cutscene. However, provide different insight or perspective of same/previous/new events can happen. This is why it sounds "none canon". But from the sound of it I guess NEW takes more priority.
I think if we choose A dialogue opotino (playsytle) over B dialogue option (playstyle) C will happen that leads to D. More prioirity on dialogue opotions that match up to their WRPG counterpart? Or if we don't do/we do a cretin thing new scenes happen as a result of not doing/doing that thing. the only two methods I can think of *shrugs*.
i think Tabata also might throw in a fun end gag just for laughs like concluding with a chocboo
I agree about the video, but there is one but. It reminds me situation when was done translation about the answer 'I dont know" from Tabata. Before spreading information, you need to check it, 1, 5 or 10 times.