I don't think From, or even Namco for that matter, had any intentions to mislead us with their material.
Around mid January, they had a pretty consistent message and were only showing actual release console footage.
There have been some inconsistencies, such as journalists still running TGS footage into February, screenshots not reflecting the actual version. These seem to be tertiary to their main marketing push and can be chalked up to ignorance rather than ill intent.
Not all the marketers working at Namco, or those involved in putting the Amazon store page together will be following the game as religiously as we are. They will not realize that using TGS marketing material will not perfectly reflect the final game.
Why didn't they update their official website or tell any of their stores/partners to replace their old material?
Most likely oversight. You are latching onto some of the inconsistencies I was referring to. Do you actually believe the developers run their website? No, they have a community manager who handles that.
Starting ~mid January all of the demos and trade shows showcased the retail version.
I just want to know the point where they decided to scrap the original vision and why.
No reason they couldn't have delivered that on PC and wowed people. Im guessing they hit a damn wall in development and the deadline necessitated the change in quality.
Money.
From knows how to pull a profit from a niche game. True that the Souls series has gained a massive following, but they may have been playing it safe with their investment.
Sure, that's why they created a tech demo that far surpasses the actual game and showed it at every trade show possible. Not to mention still using it to promote the PC version to this very day.
Vertical slice. The retail build wasn't in a playable state at that point.