>>724189578
>King not meeting the Knight
The Knight took action to influence the Card Castle Dark World before actually making the fountain, and therefore King never met them. This was a major point of contention in Kris Knight speculation (why wouldn't King recognize Kris as The Knight?) after Chapter 2 clarified how Dark Worlds and Dark Fountains worked.
>Papyrus being cancelled
Again this was in Chapter 2, and Sans fucking with you isn't a "retcon."